Safety syringe needle device with interchangeable and retractable needle platform

ABSTRACT

The syringe includes a barrel, a plunger, and an adapter for mounting the needle in the distal end of the barrel. The adapter includes a protrusion projecting away from the needle end and into the barrel defining an annular space between the barrel and the protrusion. The plunger and protrusion have complementary surfaces whereby the plunger may grip the adapter for removal of the adapter into the interior of the barrel after use. These complementary surfaces afford initial resistance to further axial movement of the plunger toward the adapter, signalling the user that further axial pressure will permanently lock the plunger and adapter to one another whereby, upon application of full axial pressure on the plunger, the complementary surfaces of the plunger and adapter permanently lock to one another to enable joint unitary movement of the plunger and adapter together with the needle carried by the adapter into the barrel. The adapter includes vent passages communicating between the central passage through the adapter and the annular space whereby air can be vented from the barrel after receiving fluid within the barrel and prior to injection. Thus, the syringe may be oriented in a vertical position needle end uppermost with the vent passages forming the most superior portion of the barrel interior whereby air may be vented.

RELATED APPLICATIONS

This is a divisional of application Ser. No. 08/917,337, filed Aug. 25,1997, now U.S. Pat. No. 5,858,000, which is a continuation-in-partapplication of application Ser. No. 08/603,868, filed Feb. 22, 1996, nowU.S. Pat. No. 5,688,240 which in turn is a divisional application ofapplication Ser. No. 08/470,026, filed Jun. 6, 1995, now U.S. Pat. No.5,520,649, issued May 28, 1996, which was a divisional application ofapplication Ser. No. 08/361,227, filed Dec. 21, 1994, now U.S. Pat. No.5,462,531, issued Oct. 31, 1995, which was a continuation-in-partapplication of application Ser. No. 08/128,694, filed Sep. 30, 1993, nowU.S. Pat. No. 5,415,638, issued May 16, 1995, which in turn is acontinuation-in-part application of application Ser. No. 07/909,385,filed Jul. 8, 1992, now U.S. Pat. No. 5,263,933, issued Nov. 23, 1993,which, in turn, is a continuation-in-part of application Ser. No.07/800,849, filed Nov. 29, 1991, now U.S. Pat. No. 5,205,827, issuedApr. 27, 1993, which is a divisional of application Ser. No. 07/687,108,filed Apr. 18, 1991, now U.S. Pat. No. 5,112,318, issued May 12, 1992,which is a continuation-in-part of application Ser. No. 07/607,127,filed Oct. 3, 1990, now U.S. Pat. No. 5,122,124, issued Jun. 16, 1992,which is a continuation-in-part of application Ser. No. 07/410,318,filed Sep. 21, 1989, now U.S. Pat. No. 5,030,208, issued Jun. 9, 1991,which was a continuation-in-part of application Ser. No. 07/327,344,filed Mar. 22, 1989, now abandoned, which was a continuation-in-part ofapplication Ser. No. 07/285,012, filed Dec. 14, 1988, now abandoned, thedisclosures of which are incorporated herein by reference.

FIELD OF THE INVENTION

This invention relates to a novel safety disposal syringe needle devicewhich has medical and industrial application. More particularly, thisinvention pertains to a syringe which, after being used by a person toinject medication or fluid into a patient, or withdraw fluids from apatient after sampling or exposure to toxic materials, or the like, canbe transformed by the person to withdraw the needle into the barrel ofthe syringe for disposal purposes, thereby eliminating needle stickinjuries among such persons.

BACKGROUND OF THE INVENTION

Needle stick injuries among medical personnel such as health careworkers are of growing concern because of disease transmission,particularly the deadly virus known as HIV-1 (AIDS) and Hepatitis B. TheAIDS virus for which there is no known cure is estimated to infect morethan twenty million people worldwide and is spreading rapidly. Althoughin 1985 medical publications stated that no health care workers hadbecome infected with the AIDS virus, it is now known that there is asignificant risk to health care workers. A report in the New EnglandJournal of Medicine, Aug. 14, 1988, indicates that the risk of acquiringHIV-1 infection is 0.35-0.74% per needle stick injury. The reportedincidence of needle stick injuries to medical staff has been reported at25.3 per 100 beds annually. In one New York hospital, at least 7% ofhouse doctors have sustained needle stick injuries while caring for AIDSpatients.

Transmission rates of Hepatitis B after needle stick exposure are muchhigher than that occurring with the HIV virus and may be 6-30%. TheCenter for Disease Control has estimated 200-300 health care workers dieannually in the U.S.A. from occupationally acquired Hepatitis B.

With presently used syringes with projecting needles, potentiallydangerous needle stick in juries are commonplace and most often occurbetween the time the medication is injected into the patient and thetime the syringe is disposed of. Most injuries occur while recapping theneedle or when disposing of it into a disposal container. However,maintenance personnel who handle disposed materials are also subject toneedle stick injuries.

At present, there is no reason to believe that the AIDS epidemic willcome to a quick end. Canada's frequency rate at the present time is100.2 cases per 1,000,000. The United States is a frightening 377.1cases per 1,000,000. In Canada, according to current data projections,the incidence of AIDS rate at least doubles every eighteen months.

A number of patents disclose syringes or the like having needleprotecting features. In spite of this there are no syringes which allowwithdrawal and safe entrapment of needles currently on the market. Thissuggests difficulties with manufacture of prior patent designs. Thesyringe which is the subject of this patent application ismanufacturable and commercially viable. In addition, after propermedical use the syringe cannot be reused and any toxic substances orinfections contained within the barrel are not accessible withoutphysical breakage of the syringe. U.S. Pat. No. 4,592,744, Jagger etal., Jun. 3, 1986, illustrates a disposable medical needle apparatuswith a self-sheathing safety needle assembly. The self-sheathing safetyneedle has a case with a small closed end and a large open end. A needleassembly is located within the case with the needle projecting throughthe small closed end. A hub is connected to the needle assembly insidethe case. The connector on the hub cooperates with a receiver on thesmall end to hold the needle assembly in the case. A flange on the hubcooperates with an inward projection in the case based from the smallend to prevent movement of the needle out of the case when the needle iswithdrawn from the opening in the small end. The nozzle of a syringepushed into the hub withdraws the needle when the syringe is withdrawn.A rubber stopper on a vacuum tube withdraws the needle after the rubberstopper turns the flange to release the connector from the receiver.

U.S. Pat. No. 4,804,370, granted Feb. 14, 1989, Haber et al., disclosesa disposable disease control syringe which reduces the frequency ofaccidental needle strikes to health care workers and preventshealth-threatening reuse of the needle cannula by drug abusers. Thesyringe includes a cylinder having an open proximal end, a substantiallyclosed distal end, and a retractable needle projecting through thedistal end. A piston assembly having a detachable stem and a needlecapturing receptacle moves axially and distally through the syringecylinder to expulse fluid medication and to selectively engage theneedle at the most distal aspect of the cylinder. The piston assembly isthen withdrawn proximally through the cylinder, whereby to relocate theneedle from the distal end to the proximal cylinder end. The needlecapturing receptacle is locked at the proximal end of the syringecylinder with the needle cannula retracted within and completelyshielded by the cylinder. The stem is then detached from the pistonassembly and discarded, thereby creating a disposal cartridge with theneedle cannula rendered permanently irretrievable therewithin.Alternatively, the piston assembly can be driven distally through thecylinder for correspondingly moving the needle into contact with apuncture resistant shield located at the distal end of the cylinder,whereby the needle is axially collapsed and destroyed within thecylinder.

U.S. Pat. Nos. 4,542,749, Caselgrandi et al., and 3,306,290, Weltman,disclose syringes with protected needle designs.

U.S. Pat. No. 4,631,057, Mitchell, discloses a syringe which has on thebody of the syringe a needle guard which can be moved from a positionwhich shields the needle, to a retracted position which exposes theneedle. U.S. Pat. No. 4,425,120, Sampson, granted Jan. 10, 1984, alsodiscloses a shielded hypodermic syringe with a needle guard mounted onthe barrel which may be extended or retracted to protect or expose theneedle. U.S. Pat. No. 4,573,976, Sampson et al., also discloses ashielded needle syringe comprising a needle guard which can be retractedor extended relative to the body of the syringe, means being providedfor releasably retaining the guard in the retracted position. U.S. Pat.No. 3,884,230, Wulff, granted May 20, 1975, discloses a flexible needleguard and device for a hypodermic syringe. This design appears to bedirected mainly to avoiding breakage of the needle when the syringe isbeing used.

U.S. Pat. No. 4,258,713, Wardlaw, discloses an automatic disposablehypodermic syringe which has means for driving the hypodermic needlefrom a retracted position within the housing of the syringe to aninjecting position whereby a portion of the needle protrudes from thehousing. This device does not disclose a feature whereby the needle canbe protected or retracted after use. U.S. Pat. No. 4,085,737 discloses ablood sampling syringe which includes an apparatus for protecting theopen end of the needle of the syringe. The device is intended forminimizing risk of contamination of the needle tip after a blood samplehas been taken. U.S. Pat. No. 4,260,543, Blum, granted May 12, 1981,discloses a hypodermic needle protection means which is designed so thatthe needle can be slidably moved to the interior of the needle supportmeans upon application of pressure.

U.S. Pat. No. 4,266,544, Wardl2w, granted May 12, 1981, discloses animproved disposable syringe wherein retracting means movably mounted onthe housing of the syringe is adapted to pull the needle from itsprojecting position to a safe position whereby the needle is covered bya portion of the syringe. U.S. Pat. No. 4,139,009, Alvarez, discloses ahypodermic needle assembly with a retractable needle cover, the needlecover comprising a plurality of elastically resilient arms extendingbetween a hub portion and a slide member, the arms acting as a restoringforce for urging the slide member back over the needle forward portionwhen the syringe is withdrawn from contact with the skin of a patient.

U.S. Pat. No. 4,774,964 discloses a device which is designed to withdrawblood from a patient. It is not a syringe per se. It is not used forinjecting fluids into a patient. However, the device has the capacity towithdraw the needle into the barrel housing.

SUMMARY OF THE INVENTION

This invention relates to a safety disposable syringe. Moreparticularly, this invention pertains to a syringe which after beingused by a health care person to inject medication or fluid into apatient or withdraw fluids from a patient, can be transformed by thatperson to withdraw the needle into the barrel of the syringe fordisposal purposes, thereby eliminating the occurrence of needle stickinginjuries among such health care persons. This syringe can also be usedin industrial processes for sampling or adding substances which may betoxic. After such function, the needle is withdrawn into the barrel toprevent contamination at any further point in the process or duringdisposal. The syringe and retractable needle feature is adapted to beused with a variety of interchangeable needles of different diameter andlength utilizing a universal Luer or Luer lock coupling mechanism.

The invention pertains to a syringe comprising: (2) a hollow elongatedbarrel means; (b) penetration means which is adapted to removably engagewith an end of the barrel means; (c) plunger means adapted to fit withinand move axially in the hollow barrel means; the plunger means causing apumping action within the interior of the barrel means between theplunger means and the end of the barrel means when the plunger means ispushed into the interior of the barrel means in the direction of the endof the barrel means; and (d) engaging means at the end of the plungermeans proximate to the penetration means, the engaging means beingadapted to engage the penetration means when the plunger means is fullyinserted into the interior the barrel means in the direction of the endof the barrel means and cause the penetrating means to part from thebarrel means and to be withdrawn into the interior of the barrel whenthe plunger means is withdrawn away from the end of the barrel means.

In the syringe, the penetrating means can be a hollow needle which ispointed at one end thereof, and at the end opposite to the pointed endis formed to mate with the penetration means engaging end of the barrelmeans. An abutting means can be positioned within the interior of thebarrel means and permits the plunger to be instead into the interior ofthe barrel means through one end but deters the plunger means from beingwithdrawn from the interior of the barrel means. Alternatively, thebarrel means may have two abutting means in the interior of the barrelmeans, the two abutting means being adapted to trap the plunger meansbetween them when the plunger means is partially withdrawn from thebarrel means.

In the syringe as defined, the engaging means may be a hook. The needleengaging means may be a female and male thread combination which isengaged by rotating the plunger relative to the barrel and penetratingmeans. Alternatively, the engaging means may be a cam-lack combination,the cam on the base of the needle penetrating means engaging with areceiving groove formed in the needle proximate end of the plunger, thecam-lock means engaging by rotating the plunger relative to the barrel.

In another version of the syringe, the end of the plunger proximate thepenetrating means can be formed with a snap-over attachment, and the endof the penetrating means proximate the plunger can be formed with aprojection which is adapted to receive and be secured by the snap-overattachment.

In a further embodiment of the syringe, the penetration means at the endproximate the plunger may be bent radially, and mate with a grooveformed in the end of the plunger proximate to the bent end of thepenetration means, the bent end of the penetration means and the groovein the plunger being engaged by rotating the plunger relative to thebarrel of the syringe.

The needle engaging means in the syringe can be a dual female threadcombination, the dual threads being formed in opposite ends of theengaging means, and a male thread means being formed on the exterior ofthe engaging means outside one of the female threads, the exterior malethread means being of opposite thread rotation to the dual female threadmeans. The end of the needle proximate to the engaging means can have amale thread removably engageable with the proximate female thread of theengaging means. The plunger proximate to the engaging means can have amale thread engageable with the female thread of the engaging meansopposite to the female thread engaging the male thread of the needlemeans.

The invention also relates to an adapter for a syringe having a pistonand a needle base fitting in the end of the syringe comprising: (a) aprotrusion formed at one end of the adapter for fitting inside thehollow of a base affixed to a syringe needle; (b) releasable engagementmeans formed in the exterior of the adapter and being adapted toreleasably engage with the interior of the needle receiving end of asyringe barrel; and (c) an engagement means formed in the end of theadapter opposite the protrusion, said engagement means being adapted toengage with the piston end of a syringe plunger.

The piston engaging means of the adapter can be a spiral thread and thereleasable engagement means can be a male thread. The penetration meansof the syringe can be releasably engaged with the end of the barrelmeans by means of an adapter, and the adapter means can be adapted toengage with the engaging means at the end of the plunger means proximateto the penetration means by rotating the plunger means. The adaptermeans can be releasably connected to the end of the barrel means by afemale-male thread combination, and the means of the adapter meansadapted to engage the engaging means of the plunger means can be aspiral thread combination with locking means.

The penetration means of the syringe can be a needle which is fittedwith a Luer lock, the Luer lack being engaged with the adapter means.The needle-Luer lock combination and the adapter can be disengaged fromthe end of the barrel means by latch means which engages with theadapter when the plunger means is pushed to the needle end of the barreland rotated to minimally withdraw and activate the engagement means.

The adapter can protrude partially from the penetration means end of thehollow barrel means and can have a thread direction which is the same asor opposite to the thread direction of the barrel means engaging thepenetration means. The adapter can be designed to protrude partiallyfrom the penetration end of a syringe barrel.

In a further embodiment of the syringe the plunger is hollow and is acircular cylinder in cross section with a fastening means such asthreads at the finger press end of the plunger. The plunger additionallyincludes a narrowed weakened break point whereby the hollow cylindricalportion of the plunger upon being withdrawn from the barrel may bebroken away and fastened to the opposite end of the barrel whether ornot the needle assembly has been withdrawn into the interior. Suchconstruction allows for redundant manners of sheathing the needleassembly through the use of a needle guard or the cylindrical portion ofthe plunger. Both include threaded ends of the same size for attachmentto the barrel and are relatively larger and more safely used than priordevices. Some additional features improve syringe function, for example,by enhancing the readability of calibration markings and thus improvingthe accuracy of the syringe.

In a still further embodiment of the invention, the needle guard and thehollow cylindrical portion of the plunger are the same element. That isto say, the circular cylinder portion of the plunger includes at anarrowed intermediate point a reusable connection means in lieu of abreak point. Such construction allows this portion of the plunger to bedisconnected from the needle end portion of the plunger and used as aneedle guard. Subsequently, this portion may be removed from the end ofthe barrel and reconnected to the needle end portion of the plunger.Moreover, such construction allows the interior of the syringe body tobe sealed at both ends when the needle end portion of the plunger iswithdrawn and the hollow cylindrical portion is in place on the barrelas a needle guard.

Additional features found in the further exemplary embodiments are theuse of colored material for the plunger, which due to its closeproximity to the inner surface of the barrel provides a less distortedor clearer background for viewing the barrel calibration markings. Stillfurther, the inclusion of a radially linear surface on the interior farend of the plunger bung, as well as using bung material of the samecolor as the plunger, presents a single flat interface whichdramatically improves the visualization of the calibration markings andthe alignment of the end of the plunger with such markings. Moreaccurate filling and delivery of contents is then possible.

Still further beneficial features of the disclosed exemplary embodimentsinclude the use of annular ridges on the interior of the barrel and/oron the exterior of the plunger whereby the sealing ridges in combinationwith a needle guard attached to the opposite end of the syringemaintains sterile conditions in the syringe interior prior to use andafter use seals bacteria or other material within the body of thesyringe.

Additional features to be found in the exemplary embodiments include acup-like annular lip or resilient pronged projections on the plungeradjacent the portion at the break point which are used in combinationwith the interior ridges of the barrel at the finger press end to deterthe needle assembly from being completely withdrawn from the interior ofthe barrel means. Such elements also retain the needle assembly at thefinger press end of the barrel. As an additional feature of theexemplary embodiments, the needle assembly includes an adapter-plungerconnection which is designed to allow unidirectional torque only so asto prevent re-attachment of the adapter to the barrel means without theuse of a special tool. Thus, subsequent use of the needle once theadapter and barrel have separated is prevented in the absence of specialtools or extraordinary measures.

A further feature of the present invention resides in the provision of aventing structure in the adapter for venting air from the interior ofthe barrel once the barrel has been substantially filled with fluid tobe injected and prior to injection. As well know, it is important thatair be expelled entirely from the barrel so that air may not be injectedwith the fluid. In certain embodiments hereof, the hub or adapter, whichreleasably secures the needle to the distal end of the barrel and isadapted to be withdrawn with the needle from the distal end of thebarrel into the interior of the barrel, has a connective structure whichenables the plunger to grasp the adapter and withdraw the adapter andneedle into the interior of the barrel. This connective structureprotrudes toward the interior of the barrel, forming an annular spacebetween it and the side walls of the barrel at the barrel's distal end.When the axially extending fluid passage passes entirely through theadapter opening into the interior of the barrel at a location spacedfrom the distal end of the barrel, there is the danger that air can betrapped in such annular space notwithstanding movement of the plungertoward the distal end to vent the air. That is, the fluid in the barrelmay occlude the central passage, and prevent the air trapped in theannular space from venting.

Therefore, in accordance with another aspect of the present inventionthe adapter is provided with one or more vent passages which open intothe annular space at the most superior portion of the hollow barrel whenthe syringe is oriented substantially vertically with the needleuppermost. Consequently, after the fluid has been withdrawn into theinterior of the barrel and the syringe oriented vertically needle endup, air is expelled through the vent passage into the central passage bymoving the plunger toward the distal end of the barrel. The centralpassage may extend wholly through the adapter whereby the vent passageforms one or more branch passages of the central passage. Alternatively,the central passage may terminate within the adapter with more ventpassages serving not only as air vents but passages for flowing thefluid through the needle during injection. To ensure that the ventpassage(s) opens at the superior position in the interior of the barrel,the face of the radially enlarged portion of the adapter facingoppositely of the distal end of the barrel may be tapered radiallyinwardly toward the distal end of the barrel. Additionally, radialgrooves may extend in the tapered adapter face and constitutecontinuations of the vent passages. Further, one or more annular groovesmay be disposed in the tapered adapter face in communication with theradial grooves and vent passages, all to ensure venting of air from thesyringe prior to use.

A further desirable feature of a syringe is that it may be packaged andsterilized in bulk and not necessarily in individual packages. However,this leaves open the possibility of tampering or inadvertent disruptionof seals and contamination. It is important, therefore, that the syringehereof embody tamperproof features. To that end, in one embodimenthereof, tamperproofing can be accomplished by applying a strip of papertape having adhesive along one side along the side of the syringecovering both the junctures of the needle guard and body of the syringeand the proximal end of the barrel and plunger. Thus, if the tape hasbeen broken or is twisted or otherwise removed from the syringe, itwould be evident that the seals at the opposite ends of the syringe havepossibly been disrupted. Similarly, in another embodiment hereof, atight shrink-wrap of plastic material may be provided about thesejunctures. Again, removal of the shrink-wrapped plastic material or atwisting or severing thereof would indicate a possible disruption of ortampering with the seals. In a further form of the invention, thesyringe may be dipped into a plastic material in liquid form whereby athin-film coating is applied to and solidified about the entire outersurface of the syringe, including the needle guard and projectingportion of the plunger. Consequently, sterility may be maintained,provided the thin-film plastic coating is not broken, while at the sametime, disruption of or tampering with the seals at the aforementionedjunctures is readily evident. The tamperproof seals may also be providedwith sterilizing radiation sensitive material to evidence that thesyringe has been sterilized and that the syringe remains sealed.

In a preferred embodiment according to the present invention, there isprovided a syringe comprising (a) a hollow, axially elongated barrel,(b) an adapter carried by the barrel adjacent a distal end thereof andremovable therefrom in response to rotation relative to the barrel, theadapter carrying a needle and providing fluid communication with theinterior of the hollow barrel, (c) a plunger axially movable in thebarrel between first and second positions relative to the barrel, (d)adapter engagement structure disposed at the distal end of the plungerand engageable with a mating connection engagement structure on theadapter, the structures having respective drive and connectiveengagement surfaces, the drive surfaces being engageable with oneanother when the plunger lies in the first position relative to thebarrel and jointly movable to enable rotation of the adapter relative tothe barrel in response to relative rotation of the plunger and barrel tocause the adapter to part from the distal end of the barrel, theconnective surfaces being engageable with one another to connect theplunger and adapter one with the other and enable the adapter, whenparted from the end of the barrel in response to joint rotation of theadapter and the plunger relative to the barrel, to be withdrawn with theneedle into the interior of the barrel in response to joint axialmovement of the plunger and the adapter in a direction away from thedistal end of the barrel and (e) a cap carried by the barrel and movablebetween a position closing the distal end of the barrel and a positionavoiding interference with the distal end of the barrel.

DRAWINGS

In the drawings which illustrate specific embodiments of the invention,but which should not be construed as restricting the spirit or scope ofthe invention in any way:

FIG. 1a illustrates a side elevation view of the needle and hubcomponents of a first embodiment of the syringe;

FIG. 1b illustrates a side elevation view of the barrel of a firstembodiment of the syringe;

FIG. 1c illustrates a side elevation view of the plunger, bung and hookof a first embodiment of the syringe;

FIG. 1d illustrates an end elevation view of the hook;

FIG. 2 illustrates a side elevation partial-section view of a firstembodiment of the syringe assembly with the needle and hub secured to anend of the barrel, and the plunger and its bung and hook partiallyinserted into the interior of the barrel, prior to use of the syringe;

FIG. 3 illustrates a side elevation partial-section view of a firstembodiment of the syringe assembly with the plunger and its bung andhook fully inserted into the interior of the barrel so that the hookextends into the interior of the hub;

FIG. 4 illustrates a side elevation partial-section view of a firstembodiment of the syringe with the plunger, bung, hook and needle fullywithdrawn into the interior of the barrel and the distal end of theplunger broken-off from the bung end of the plunger;

FIG. 5 illustrates a side elevation partial section view of analternative embodiment of the syringe which has a double screw actionneedle and hub engagement mechanism and the end of the plunger away fromthe needle and hub engagement mechanism has therein a cavity which canfit over the opening in the end of the plunger after the needle and hubare withdrawn into the interior of the barrel;

FIG. 6 illustrates a detail view of the double screw action needle andhub engagement mechanism;

FIG. 7 illustrates a side elevation partial section view of the needleand hub withdrawn into the interior of the barrel and the broken awaypart of the plunger placed over the opening in the head end of thebarrel.

FIG. 8 illustrates a side elevation partial-section view of a secondembodiment of the syringe with a screw-lock plunger-needle hubconnection;

FIG. 9 illustrates a detailed side elevation partial-section view takenalong section A--A of FIG. 11 of a first design of a plunger with aright-hand or left-hand cam-lock rotation to secure the plunger to theneedle hub for withdrawing the needle into the barrel of the syringe;

FIG. 10 illustrates a detailed side elevation partial-section view takenalong section A--A of FIG. 11 of a second design of a plunger with aright-hand or left-hand cam-lock rotation to secure the plunger to theneedle hub and a second right-hand or left-hand rotation locking meanswhich provides a double locking action between the plunger and needlehub;

FIG. 11 illustrates an end elevational view of the needle end of thesyringe illustrated in FIG. 8;

FIG. 12 is a section view taken along section line B--B of FIG. 9showing the syringe barrel handle and syringe plunger handle at a 45°angle to one another to activate the right-hand rotation cam lockingaction;

FIG. 13 illustrates a detailed side elevation partial-section view ofside scoring on a plunger of a syringe with an oval flange cam lock;

FIG. 14, which appears on the same sheet as FIG. 11, illustrates adetailed end elevation view of the cam lock mechanism of the embodimentof the syringe illustrated in FIG. 9;

FIG. 15 illustrates a top elevation partial-section view of a plungerwith a snap-on socket type needle hub connection;

FIG. 16 illustrates a side elevation partial-section view of a plungerwith a snap-on socket type needle hub connection;

FIG. 17 illustrates a top elevation partial-section view of a plungerwith a snap-on socket type needle hub connection combined with aright-hand rotation option;

FIG. 18 illustrates a section view taken along section line A--A of FIG.16;

FIG. 19 illustrates a side elevation partial-section view of a bentneedle embodiment of a needle hub connection;

FIG. 20 illustrates a top elevation partial-section view of a bentneedle embodiment of a needle hub connection;

FIG. 21 illustrates a side elevation partial-section view of a bentneedle embodiment of a needle hub connection coupled with a right-handrotation option;

FIG. 22 illustrates a detailed end view of the diagonal slot in the endof the piston-plunger with the bent needle end fitted in the slot;

FIG. 23 illustrates a detailed end view of the diagonal slot in the endof the piston-plunger rotated in the slot to grip the bent end of theneedle;

FIG. 24 illustrates a side elevation partial-section view of anembodiment of the syringe wherein the needle and hub are rotatablydetachable from the barrel and the plunger threadedly engages theinterior of the hub;

FIG. 25a illustrates a side elevation partial-section view of thesyringe with the needle and hub drawn within the interior of the barreland the remote end of the plunger that is broken away, formed with ahollow threaded cap-like opening;

FIG. 25b illustrates a side elevation partial-section view of thesyringe with the broken away plunger portion threadedly engaged with themale threaded end of the hub at the top of the barrel;

FIGS. 25c and 25d illustrate sequential side elevation views of analternative design of syringe where the part of the plunger adjacent thebreak away weak point is threaded and is screwed into the opening in theend of the barrel vacated by the needle and hub when pulled into thebarrel;

FIG. 26 illustrates a side elevation partial-section view of anembodiment of the syringe wherein the piston is adapted with a latchwhich snaps into place in an adapter after the piston is fully depressedand rotated;

FIG. 27 illustrates a side elevation partial section view of an adapterwhich mates with the needle platform;

FIG. 28 illustrates a side elevation section view taken along sectionline C--C of FIG. 2g;

FIG. 29 illustrates an end view of the latch mechanism of the pistondepicted in FIG. 26;

FIG. 30 illustrates a side elevation view of an alternative design ofadapter;

FIG. 31 illustrates a side elevation partial section view of thealternative design of adapter;

FIG. 32 illustrates a side elevation partial section view of anembodiment of the syringe wherein an adapter is mounted allowing Luerlocked needles to be used and interchanged but permitting subsequentwithdrawal of a used needle and adapter into the barrel;

FIG. 33 illustrates a perspective view partially in phantom of a stillfurther embodiment of a syringe, a needle guard and the threadedconnection therebetween;

FIG. 34 shows a side elevation view partially in section of the syringeembodiment of FIG. 33;

FIG. 35 illustrates a different side elevation view of the embodiment ofFIG. 33 in partial section view and with the needle guard removed;

FIG. 36 illustrates a manner in which the plunger may be rotated withrespect to the barrel in order to disconnect the needle assembly fromthe barrel for withdrawal of the assembly into the barrel;

FIG. 37 is a side sectional view similar to that illustrated in FIG. 34but with the needle assembly unfastened from the distal end of thebarrel and with the assembly withdrawn into the barrel;

FIG. 38 is a side sectional view similar to that illustrated in FIG. 37but with the hollow cylindrical portion of the plunger broken away atthe break point;

FIG. 39 is a side elevational view partially in section with the hollowcylindrical plunger portion fastened to the distal end of the barrelafter the cylindrical plunger portion has been broken away at the breakpoint;

FIG. 40 is a perspective view partially in section of the adapter andthe distal end of the plunger illustrating the mating relationship ofthe noted elements;

FIG. 41 is an axial view illustrating a pair of resilient prongs used toengage a groove at the finger press distal end of the barrel forretaining the needle assembly in the retracted position in the barrel;

FIG. 42 is a partial side view of the pronged latching device of FIG.41;

FIG. 43 is a side elevational view partially in section of a stillfurther exemplary and presently preferred embodiment of the invention;

FIG. 44 illustrates a section view of a portion of the plunger takenalong section line 44--44 of FIG. 43;

FIG. 45 is a detailed partial side elevation view of a portion of theplunger including the narrowed portion of the plunger which contains thebreak point as illustrated in FIG. 43;

FIG. 46 is an enlarged sectional view illustrating a portion of theradially linear interface between the adapter and the plunger bung;

FIG. 47 is an enlarged partial sectional view of ridges and anintervening groove on the inside surface of the barrel at the distal endand a corresponding annular ridge on the exterior surface of the hallowportion of the plunger which cooperates with the annular barrel ridgesfor locking and sealing purposes;

FIG. 48 is a side elevational view partially in section of a stillfurther embodiment of the invention which represents a modification ofthe embodiment of FIG. 43;

FIG. 49 is a side elevational view partially in section of theembodiment of FIG. 48 illustrating the cylindrical plunger portiondisconnected from the needle end portion of the plunger;

FIG. 50 illustrates a partial end view of the plunger taken along line50--50;

FIG. 51 is a perspective view of an adapter constructed in accordancewith a still further embodiment of the present invention;

FIG. 52 is an enlarged fragmentary cross-sectional view illustrating theadapter of FIG. 51 disposed in the distal end of the barrel;

FIG. 53 is a view similar to FIG. 52 illustrating a further form of theadapter;

FIG. 54 is a perspective view of one form of a tamperproof syringeconstructed in accordance with the present invention;

FIG. 55 is an enlarged fragmentary cross-sectional view with partsbroken out illustrating another form of a tamperproof syringe;

FIG. 56 is an enlarged side elevational view with parts broken out andillustrating the opposite ends of a syringe having a tamperproof coatingaccording to the present invention;

FIG. 57 is a side elevational view of a syringe with the barrel endcapped prior to use:

FIGS. 58 and 59 are enlarged side elevational views of two additionalembodiments of caps for capping the end of the syringe barrel;

FIG. 59A is an enlarged fragmentary elevational view illustrating a capwith a hinge connecting the cap and the syringe barrel to one another;

FIGS. 60-62 are side elevational views schematically illustrating theseries of steps for re-applying the cap illustrated in FIG. 58 to thebarrel end of the syringe after use of the syringe; and

FIGS. 63 and 64 are side elevational views of a further form of syringehereof and illustrating its manner of use.

FIGS. 65-69 are fragmentary cross-sectional views of a still furtherembodiment of syringe hereof wherein the plunger is permanently lockedto the adapter upon axial displacement of the plunger into final seatedposition relative to the adapter;

FIGS. 70 and 71 are enlarged views similar to the embodiments of FIGS.65-69, illustrating a still further embodiment for permanently lockingthe plunger and adapter to one another;

FIG. 72 is a view similar to FIG. 70 illustrating a still furtherembodiment of the syringe hereof;

FIG. 73 is a schematic illustration of the coupling between the proximalend of the plunger and the distal end of the barrel once the adapter andneedle have been withdrawn into the barrel;

FIGS. 74 and 75 are cross-sectional views of the embodiment of FIGS.65-69 taken generally about on lines 74-74 and 75-75 in FIG. 65;

FIGS. 76 and 77 are views similar to FIGS. 74 and 75 taken generallyabout on lines 76-76 and 77-77 in FIG. 69;

FIG. 78 is a fragmentary cross-sectional view illustrating an adapterand plunger end combination in accordance with a further form of thepresent invention; and

FIG. 79 is a view similar to FIG. 78 illustrating the adapter andplunger end in engagement with one another in the end of a syringebarrel.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

Most disposable syringes can be used with a variety of interchangeableneedles with different diameter and length. The needles are connected bywhat is known as a Luer connector, which may be of two types. One is asimple conical device which accepts the needle base. This version isoften described as a Luer tip. To detach-the needle, it is simply pulledoff. The other connector type is often described as a Luer lock. TheLuer lock has a simple screw thread locking mechanism that permits thebase of the needle to be screwed onto the syringe so that it cannot bepulled off without unscrewing. In this disclosure, the universalcoupling mechanism connecting the needle to the syringe will be referredto as a Luer lock version of the Luer connector unless otherwiseindicated. It should be recognized that the claims to the inventionrelate to both the plain Luer tip and the Luer lock mechanisms. Theinterchangeability capability of a Luer lock allows for the mostappropriate needle to be used for syringe filling and patient injection.In many cases, to save time, a different larger needle is used to fillthe syringe with fluid prior to injection. A needle of fine caliber tominimize pain to the patient, and tissue damage, is often used forintramuscular or subcutaneous injection. In addition, if the same needleis used to puncture a vial in order to fill the syringe with medication,there is a potential for contamination of that needle from the vial, ifthe vial stopper carries a contaminant. Under most circumstances, thiswould not pose a significant risk. However, if the patient has reducedimmunity to infection, the ability to change to an entirely new sterileneedle for patient injection may become important.

Although the prior art describes syringes which can protect the needleby a variety of means, including those which involve withdrawing theneedle into the interior of the barrel of the syringe, such syringes donot allow for interchangeability of the needle or for the universal Luerlock coupling mechanism which is an important feature of the syringe.Most commercially available syringes employ a Luer lock. Since thesubject invention is adapted for use with a Luer lock, it can directlyreplace syringes currently in use and requires no change in technique orprocedure until after the syringe has been used. In addition, mostcurrently produced needles can be used in the usual manner on thissyringe.

After use, once the needle has been withdrawn into the barrel, thesyringe plunger can be snapped off. It is designed so that it can bescrewed onto the front of the syringe and thereby prevent anypossibility of the needle within the barrel protruding through the frontof the syringe again. This is an important factor for a health careworker using the syringe and also for any health care workerssubsequently handling garbage which might contain a contaminatedsyringe.

This invention pertains to a syringe which, after being used by a healthcare worker or hazardous industries worker, or the like, to injectmedication or fluid into a patient, or withdraw fluid from a patient, orin sampling toxic material, for example, in an industrial process, canbe transformed by the worker to withdraw the needle into the barrel ofthe syringe for disposal purposes, thereby eliminating potentiallyharmful needle stick injuries among such workers. In industrialapplications, the storage of a contaminated needle is similarly effectedwithin the barrel to prevent further contamination of the environment orprocess.

With any one of the various embodiments of the basic syringe design, theneedle is retracted by the user into the interior of the body of thesyringe immediately after it is withdrawn, or during its withdrawal,from the patient's body tissue, or after exposure to hazardoussituations. Thus, the needle is not exposed for accidental contact atany time after the needle has contacted the potentially hazardouspatient's body fluids, or other hazardous materials. This retractionfeature eliminates the possibility of potentially dangerous needle stickinjuries occurring with contaminated needles.

The safety syringe of the invention is simple to operate and is onlyslightly more expensive to manufacture than presently used syringes.Another advantage is that the syringe design closely resembles currentlyused syringes and thus there should be no difficulty in obtaining goodacceptance among workers such as medical institutional workers since:the syringe is hermetically sealed before and after use; redundancy ofmechanisms allows safe disposal and protection from needle stickinjuries and accuracy of reading calibration markings for filling ofsyringe is more precise.

Moreover, the operation of the subject syringe is easy to teach to suchworkers and requires no unusual skills or manual dexterity.

Syringes that are in current commercial use normally consist of fourcomponents, a needle cap which is removed prior to use, a hollow needlewhich is mounted on a hub with a Luer lock, a barrel to which the hub isattached, and a plunger with a bung (piston) at the head end of theplunger. The plunger is inserted within the barrel head end first andcan be pushed into the interior of the barrel in order to pump fluidcontained in the barrel out through the interior of the hollow needle.The subject invention, in various embodiments, includes several basicmodifications which do not dramatically change the appearance of theconventional syringe.

Referring to the drawings, FIGS. 1a, 1b and 1c illustrate the threebasic components which make up a first embodiment of the novel needleretractable syringe. FIG. 1a illustrates in side elevation partialsection view the construction and interaction of the needle 2 and cup 4which fits detachably within the interior of hub 6 of the syringe. Hub 6has a female thread in the base of its interior. FIG. 1b illustrates inside elevation partial section view the construction and interaction ofthe barrel 8, the partially closed threaded hub receiving end 10, whichis located at the top of the barrel 8, and the barrel base 12 which isformed at the bottom of the barrel 8. A circular rim-like catch 14 isformed in the interior of the barrel 8 immediately above the barrel base12 and provides a stop to deter full withdrawal of the plunger 16 fromthe interior of the barrel 8. Alternatively the needle may duringmanufacture be affixed integrally to the syringe base and be removableonly during retraction into the barrel after the syringe has been used.

FIG. 1c illustrates the construction of the plunger 16, which includes abung (piston) 18 which fits snugly against the interior of the barrel 8and serves to force the liquid contents of the interior of the hollowbarrel 8 (usually medication) out the interior of the hollow needle 2,and in a common situation into the body of a patient, when the plunger16 is manually pushed into the interior of the barrel 8. A thumb orfinger press 20 is formed at the base of the plunger 16, while the base22 of the bung 18 serves to align the plunger 16 within the interior ofthe barrel 8, and deter full withdrawal of the plunger 16 from thebarrel 8 by abutting catch 14. Affixed to the top central area of thebung 18 is a five tine metal hook 24.

FIGS. 2, 3 and 4 illustrate in sequential side elevation partial-sectionviews, the syringe in assembled state, with the components in variouspositions. FIG. 2 illustrates the syringe assembly when it is chargedwith a fluid such as fluid medication, or the like, ready for use. Thefluid is contained in the volume space immediately above the bung 18 andbelow the threaded hub receiving end 10. When the plunger 16 is fullypushed by the thumb or finger press 20 upwardly into the interior of thebarrel 8, the fluid contents of the syringe are extruded by plunger 16and bung 18 through the hollow interior of needle 2 and out the pointedend. At the same time, one or more of the tines of the hook 24 engageswith the interior of cup 4 as illustrated in FIG. 3. Subsequently, asillustrated in FIG. 4, when the plunger 16 is almost fully withdrawnfrom the interior of barrel B, the hook 24 pulls the cup 4, and theattached needle 2, downwardly through the interior of hub 6, and intothe interior of barrel S. Thus all of the needle 2 is retracted into theinterior of the barrel 8. If desired, the portion of the plunger 16which extends beyond base 12 can be broken off at the weakened section,as illustrated in FIG. 4, and the two components disposed of in smallerpieces.

As seen in FIG. 1a, the metal of the needle is extended to form a bellshaped cup 4, which fits within the interior of and is affixed to theplastic hub 6. By using this construction, in this embodiment, thelikelihood that a break will occur between the needle 2 and the cup 4 isminimized. The needle 2 and the cup 4 are formed in one piece, and sincethe metal is stronger than the plastic forming the hub 6, a breakbetween the metal and the plastic is encouraged.

When the plunger 16 is fully depressed into the interior of the barrel8, the one or more of the tines of hook 24 engage the interior of thecup 4, and then, when the plunger 16 is withdrawn, the hook 24 pulls onthe interior of the cup 4 and causes it to break away from hub 6. Once afull break has been made, needle 2 and cup 4 are drawn into the interiorof the barrel 8 by further withdrawing the plunger 16.

The syringe of the invention has a built-in safety feature in that theneedle 2 can only be withdrawn into the interior of the barrel 8 up tothe point that guide 22 abuts the catch 14 located around the interiorrim of the base of the barrel 8. Thus, unless considerable effort isexerted, it is not possible to pull the needle 2, cap 4 and plunger 16completely through the barrel 8. The catch 14 is designed so that whenthe components are assembled, it is easy to insert the bung 18, with thehook 24, and the guide 22 through the interior of the one-way catch 14,and into the interior of the barrel 8 but it is difficult to fullywithdraw these components. Once the needle 2 is withdrawn into thebarrel 8 by hook 24, it is not supported laterally and tips to one sideagainst the barrel 8, thereby making it virtually impossible to push theneedle 2 back through the hub 6. The tines of hook 24 are notnecessarily of the same length, which encourages tipping of the needle 2to one side. Breaking off the portion of the plunger 16 that extendsbeyond barrel base 12 ensures that the used needle 2 cannot be pushedback through hub 6, thereby exposing the sharp point of the needle 2beyond hub 6. Also, it is usually easier to dispose of two smallershorter components than one elongated one.

FIG. 5 illustrates a side elevation partial section view of a preferredembodiment of the syringe which has a double screw action needle and hubengagement mechanism 80. The end of the plunger 16 away from the needleand hub engagement mechanism 80 has therein a cavity 82 which can fitover the cup 84 and opening in the end of the barrel 8 after the needle2 and hub 6 are withdrawn into the interior of the barrel 8 (see FIG.7).

FIG. 6 illustrates a detail view of the double screw action needle andhub engagement mechanism 80. The mechanism 80 is constructed so that ithas right hand female threads 86 of one size diameter in a cup-likeopening at one side, a right hand female thread 88 of a narrower sidediameter in a cup-like opening in the opposite side, and a left-handmale thread 90 on the exterior of the mechanism 80 outside the interiorfemale thread 88.

Hub 6 screws into female thread 88 and the syringe is used in thisconfiguration for injecting medication into a patient. However afteruse, to operate the mechanism 80, to enable the needle to be withdrawninto the barrel 8, the head end of the plunger and bung 18 are screwedright handed into the female thread 86. Once fully engaged, then furtherright hand action on left-handed thread 90, unscrews thread 90. Theentire mechanism 80 including the needle 2 can then be withdrawn intothe interior of the barrel 8. The right hand and left hand threads can,of course, be reversed to operate in the reverse manner, if that isrequired.

FIG. 7 illustrates a side elevation partial section view of the needle 2and hub 6 withdrawn into the interior of the barrel 8 and the cavity 82of the broken away part of the plunger 16 placed over the opening andcup 84 in the head end of the barrel 8.

FIG. 8 illustrates a side elevation partial-section view of a secondembodiment of the syringe which is constructed to have a screw-lockplunger-needle hub connection. As can be seen in FIG. 8, the barrel 8has the syringe plunger 16 disposed therein. The plunger 16 carries atits frontal end (the left end as seen in FIG. 8) a piston 26 which isconstructed of a resilient material such as resilient rubber so that itsnugly engages the inner cylindrical surface of the barrel 8. The piston26 is connected to the plunger 16 by means of a plunger flange 36. Thefrontal end of the plunger 16 is constructed to have therein acylindrical cavity which has a female thread 28 formed in the wall ofthe cavity. The base of the hub 6 is constructed to have a male hubthread 34, which is formed to match and engage the female thread 28formed in the opening in the front end of the plunger 16. FIG. 8 alsoillustrates piston stop 15 formed in the rear end of the interior of thebarrel 8 (the right side as seen in FIG. 8). Piston stop 15 serves thesame purpose as catch 14 as discussed in relation to FIGS. 1 to 4 above.A cap 32 protects the needle 2 and fits over the hub 6. Cap 32, whenengaged after the needle 2 is withdrawn prevents exposure of the needle2 if it is accidentally pushed back through the opening at the forwardend of the syringe.

In use, the plunger 16 and piston 26 are disposed within barrel 8 asillustrated in FIG. 8. The cap 32 is removed and the pointed end of theneedle 2 is inserted into the medication. At this time, female hubthread 34 is not engaged in male thread 28. The fluid medication isdrawn into the interior of the barrel 8 by suction action created bywithdrawing press 20 and plunger 16 from the interior or barrel 8, as isconventional. Once the desired quantity of medication has been drawninto the interior of the barrel 8, and air is eliminated, the sharp endof the needle 2 is inserted into an appropriate location on the patient.The medication that is held within the interior of barrel 8 is injectedthrough the interior needle 2 into the patient by asserting thumb orfinger pressure on press 20. Once the medication has been injected intothe patient, the piston 26 has moved to the position illustrated in FIG.8. It is then necessary to initiate the action which is ultimately usedto withdraw the hub 6 and the needle 2 into the interior of the barrel8. This is done by asserting a clockwise rotation on press 20, whichengages male hub thread 34 in female thread 28 in the end of plunger 16(assuming that threads 28 and 34 are right-hand threads). Hub 6 andplunger 16 are then intimately engaged by threads 34 and 28 interactingwith each other. Press 20 can then be withdrawn to pull the plunger 16from the interior of barrel 8. By this action, the hub 6 and needle 2are pulled into the interior of barrel 8 until the rear end of piston 26comes to rest against piston stop point 15. At this point, the plungerbreak point 30 has been withdrawn exterior of the barrel 8, andconsequently plunger 16 can be broken into two parts at the plungerbreak point 30. The two parts of the syringe can then be disposed ofwith complete safety since the needle 2, which might have been exposedto harmful virus, or the like, has been withdrawn into the interior ofbarrel 8, while the part of the syringe 16 that has been broken away atbreak point 30, has not been exposed to any medicine and can bediscarded without danger. It will be recognized that break point 30 isan option which need not necessarily be built into plunger 16. Breakingthe syringe into two parts permits easy disposal whereas one elongatedsyringe, with the plunger withdrawn might be difficult to dispose of incertain instances.

FIG. 9 illustrates a detailed side elevation partial-section view takenalong section line A--A of FIG. 11 of a first design of a piston 26 witha right-hand cam-lock rotation (rather than a thread configuration) tosecure the forward end of the piston 26 to the needle hub 6 forwithdrawing the needle 2 into the barrel of the syringe. The cam-lockoption illustrated in FIG. 9 operates by asserting a right-hand rotationon the press 20, relative to the barrel 8. In this way, cam-lock ridge42, which is formed in the base of hub 6, rotates into helicalengagement with cam-lock groove 44. This combination replaces the malehub thread 34 and female thread 28 combination illustrated in FIG. 8, asdiscussed previously. Once the cam-lock ridge 42 is engaged snuglywithin cam-lock groove 44, the needle 2 and hub 6 can be withdrawn intothe interior of the barrel 8.

FIG. 10 illustrates a detailed side elevation partial-section view of asecond design of a plunger with a right-hand cam-lock rotation (similarto that illustrated in FIG. 9). However, the design shown in FIG. 10also includes a second hub rim 38 which is formed in the base area ofhub 6. The purpose of hub rim 38 is to engage left hand thread 40, whichis formed in the interior of the barrel 8, which houses the hub 6. Thealternative option illustrated in FIG. 10 includes the right-handcam-lock ridge 42, cam-lock groove 44 combination, discussed inassociation with FIG. 9, but it has a second feature. A right-hand malehub rib 38 is formed in the exterior of hub 6 forward of cam-lock ridge42. A matching right hand female thread 40 is formed in the interior ofthe forward end of barrel 8, that is, the end which surrounds hub 6. Tooperate the double action embodiment illustrated in FIG. 10, cam-lockridge 42 is first engaged in cam-lock groove 44 by clockwise (righthand).rotating press 20 relative to barrel base 12 (see FIG. 8) andthen, by means of a second right handed (counterclockwise) rotation, hubrim 38 is engaged within female left hand thread 40. The needle 2 andhub 6 are then double engaged by two right hand twists and can then bewithdrawn into the interior of the barrel 8. The double-actionengagement mechanism ensures proper secure engagement of the plunger andhub.

It should be recognized that the first and second options illustrated inFIGS. 9 and 10 respectively can be used in any of the alternativeembodiments of the invention that are illustrated in FIGS. 11 through23. It should also be recognized that the double-action lockingmechanism illustrated in FIG. 10 can be right-right, left-left,right-left or left-right.

FIG. 11 illustrates an end elevation view of the needle end of thesyringe illustrated in FIG. 8, and clearly illustrates the eccentricconstruction of right-hand cam-lock ridge 42. Ridge 42 is constructedgenerally in the form of an oval, the opposite ends of the oval beingadapted to engage in the right-hand grooves of the cam-lock groove 44(see FIG. 9 or 10).

FIG. 12 is a section view taken along section line B--B of FIG. 9 andillustrates the syringe barrel base 12 and the press 20 rotatedclockwise 45° relative to one another. This clockwise action engagescam-lock ridge 42 in cam-lock groove 44.

FIG. 13 illustrates in detail a side elevation partial-section view ofright-hand side scoring on the interior frontal opening a plunger of thesyringe adapted for use with the oval flange cam-lock. As can be seen,by means of the helically angled right-hand groove 44, the right-handoval shaped ridges 42, when they become mated in the interior of thepair of cam-lock grooves 44, rotate relative to one another in a helicalfashion, thereby creating a secure fit.

FIG. 14 illustrates a detailed end view of the cam-lock mechanism of theembodiment of the syringe illustrated in FIG. 9. Barrel 8 and cam-lockridge 42 are shown in solid lines. The dotted lines represent thecam-lock groove 44.

FIG. 15 illustrates a top elevation partial-section view of a plunger 16which is equipped with an alternative design engaging mechanism, namelya snap-on socket-type needle hub connection. FIG. 16 illustrates a sideelevation view of the snap-on socket type needle hub connectionillustrated in FIG. 15. As can be seen in these two illustrations, theforward end of the plunger 16 is constructed so that it has a snap-on"fastener 46, which, when the plunger 16 is pushed strongly (in aleftwardly direction as seen in FIG. 16) snaps over and embraces thelongitudinal knob-like end 48 that is formed in the base of hub 6. Thesnap-on fastener 46 and knob 48 engagement combination is an alternativeembodiment which replaces the cam-lock ridge 42 and cam-lock groove 44combination illustrated in FIGS. 9 through 14, as discussed previously.Unlike the thread combination 28, 34 (FIG. 8) and cam-lock combinations(FIGS. 9 to 14), no rotational action is required to engage fastener 46and knob 48. Once snap-on fastener 46 has been pushed over snap-overknob 48, the hub 6 and needle 2 can be withdrawn into the interior ofbarrel 8 by pulling press 20 from the barrel 8.

FIG. 17 illustrates the snap-on fastener 46-snap-over knob 48 embodimentdiscussed previously in relation to FIGS. 15 and 26, but includes theoption a righthand hub rim 38 and a right hand option thread 40secondary engagement mechanism (as discussed in detail previously inassociation with FIG. 10).

FIG. 18 illustrates a section view of the syringe taken along sectionline A--A of FIG. 16. The rectangular construction of the snap-onfastener 46, which fits over snap-over knob 48, can be readily seen.Also visible in FIG. 18 are the plunger, flange 36 (shown in dottedlines), barrel 8, needle 2, and barrel base 12. FIGS. 15 to 18illustrate a cylindrical embodiment. It should be understood thatalternative shapes such as hexagonal or octagonal can be used. Theadvantage would be that such a configuration would allow for rotarymovement to be transferred to the needle assembly and allow it to bebroken away by rotation rather than by simple traction.

FIGS. 19 and 20 illustrate respectively side and top elevationpartial-section views of a further alternative engaging mechanism,namely a bent needle hub engaging embodiment of the syringe. FIG. 19,which depicts the side elevation view, incorporates the first option(that is, without optional hub rim 38, and right hand thread 40combination). FIG. 19 shows how the base end of the needle 2 is bent atright angles to form an upwardly projecting end 50. The end 50 fits intoa slot and groove 52, which is formed in the forward end of the plunger16. By rotating the plunger 16, and piston 26 about 90° relative to end50, the end 50 engages in slot 52, thereby securely connecting the headend of plunger 16 with hub 6 and needle 2. This engagement allows thehub 6 and needle 2 to be withdrawn into the interior of the barrel 8, asdescribed previously. FIG. 21 illustrates the bent needle embodimentthat was discussed above in relation to FIGS. 19 and 20, but includingthe option of a hub rim 38, and right hand thread 40, formed in the hub6 to provide a double engagement mechanism. As mentioned previously,either option 1 or option 2 (FIG. 9 or 10), can be utilized in allembodiments of the syringe as discussed.

FIGS. 22 and 23 illustrate a detailed end view of slot 52 and needle end50, the slot 52 being formed in the head end of the plunger 16. The bentneedle end 50 is first inserted in slot 52, as illustrated in FIG. 22,and then the end 50 is rotated 90° into a groove opening formed in theinterior of the plunger 16, thereby engaging the base end of the needle2 with the plunger 16.

FIG. 24 illustrates a side-elevation partial-section view of anembodiment of the syringe wherein the needle and hub are rotatablydetachable from the barrel and the plunger threadedly engages theinterior of the hub. The base of the needle 2 is threadedly andremovably engageable with the hub 63 by threads 62. In turn the hub 63is threadedly and removably engageable with the barrel 8 by thread 64.The head end of the plunger 16 can engage with the interior of the hub63 by interior threads 65 and withdraw needle 2 and hub 63 into theinterior of the barrel 8. The interior of the head end of barrel 8 isshaped like an "M". The angled ends deter the needle 2 from pushing backthrough the opening in the end of the barrel 8.

FIG. 25a illustrates a side elevation partial-section view of thesyringe with the needle and hub drawn within the interior of the barreland the remote end of the plunger that is broken away, formed with ahollow threaded cap-like opening and FIG. 25b illustrates aside-elevation partial-section view of the syringe With the broken awayplunger portion threadedly engaged with the male threaded end of the hubat the top of the barrel.

As shown in FIG. 25a, the hub 6 can be formed so that it has malethreads 70 around its circumference. Correspondingly, a mating cavitywith mating female thread 72 can be formed in the thumb press end ofplunger 16. If need be, the thumb press end of plunger 16 can be widenedat location 74 in order to accommodate the cavity with the female thread72.

With this embodiment, when the plunger 16 is broken away at break point30, it can be used to cover the open end of syringe 8 by screwing femalethreads 72 onto male threads 70 of hub 6. In this way, both ends of thebarrel 8 are closed, and there is no way that the potentiallycontaminated needle 2 can escape the interior of barrel B.

Alternatively, once the plunger has been broken, the end distant fromthe thumb press and proximate to the fracture site can be fashioned toallow it to fit snugly or screw into the now open end of the barrel(from which the needle has now been withdrawn into the barrel). Ifrequired, a second fracture site (not shown) can be fashioned in theplunger. This permits the plunger to be broken off at either of the twofracture sites according to the performance of the user.

FIGS. 25c and 25d illustrate sequential side elevation views of analternative design of syringe where the part of the plunger 16 adjacentthe breakaway weak point 30 is threaded at 78 and is screwed into femalethreads 76 of the opening in the end of the barrel 8 vacated by theneedle 2 and hub when pulled into the barrel 8.

FIG. 26, illustrates a side elevation partial-section view of anembodiment of the syringe wherein the piston is adapted with a latchwhich snaps into place in an adapter (platform) after the piston isfully depressed and rotated clockwise. The embodiment illustrated inFIG. 26 depicts the needle 2 embedded in a Luer lock 100, associatedwith the constricted end 10 of syringe barrel B. The plunger 16 with afinger press 20 at the remote end thereof is positioned inside barrel 8.A stop rib 14 prevents the plunger 16 from being totally withdrawn fromthe interior of the barrel 8. Bung 18, which provides a tight fit withthe interior of barrel 8, is mounted on the end of plunger 16 oppositefinger press 20.

The operative needle engagement and detachment mechanism illustrated inFIG. 26 is a combination of an adapter 102, which cooperates with Luerlock 100, the combination fitting into the narrow end 10 of barrel 8.The end of plunger 16 opposite finger press 20 has a latch mechanism 104formed inside bung 18. A pair of prongs 106 are formed in latch 104 andengage into grooves 108 in adapter 102 when the plunger 16 is rotated ina clockwise direction. Once the pair of prongs 106 engage in therespective grooves 108 of the adapter 102, then the plunger 16 isrotated further clockwise which then, because of the left hand threads110 engaging the interior of the narrow end 10, causes the adapter, andthe needle with the Luer lock 100, to disengage from the narrow end 10.At this point, the needle 2, Luer lock 100, adapter 102, and bung 18 canbe withdrawn into the interior of the barrel 8 by pulling finger press20 away from the narrow end 10 of the syringe.

As can be recognized, the adapter 102 is an important feature of thisembodiment of the invention. The adapter enables a standard Luer lock100 to indirectly mate with latch 104 at the end of plunger 16.Moreover, the adapter 1 10 is designed so that it accommodates differentsides of needle 2 and Luer lock 100.

FIG. 26 illustrates a narrow point in the plunger which assists inbreaking the plunger in two. If required, or desirable, two or moreadditional narrow points can be included to permit breakage atalternative locations.

FIG. 27 illustrates in side elevation partial section view a preferredembodiment of the adapter 102. Nose 112 is adapted to fit inside thehollow of a standard Luer lock 100. The left hand thread 1 10 is alsoshown in FIG. 27. The adapter 102 has opposite the nose 112 a cup-likeedge 114 which is formed to receive the front end of latch 104. Formedinside the rim of cup 114 is a protrusion 116 which has a pair of fastacting spiral male threads 118 formed thereon. Prong engaging grooves108 are also formed in the interior of the protrusion 1 16 at the pointwhere the protrusion 116 joins with the cup 114. The advantage of thisadapter design is that with the fast acting spiral threads 118 forcealignment without jamming. Full axial movement is possible with norotation forced by the alignment threads. Then after full depression ofthe plunger, rotation will disengage the adapter 102 and allow theprongs 106 to engage in grooves 108. Rapid engagement between the prongs106 in grooves 108 is achieved by minimal rotation of the plunger 16. Atthat point, further clockwise rotation of the plunger 16 by means offinger press 20 causes the threads 110 of adapter 102 to disengage fromthe interior narrow end 10. The needle 2 assembly can then be withdrawninto the interior of barrel 8.

FIG. 28 illustrates a section view taken along section lines C--C ofFIG. 29 and depicts a detailed view of the construction of the latch 104and prongs 106. In the embodiment illustrated in FIG. 28, the latch 104has a pair of alignment ridges 120 formed in the interior of latch 104.These alignment ridges 120 assist engagement of the latch 104 withadapter 102.

FIG. 30, which illustrates a side view of an alternative design ofadapter 102, and FIG. 31, which illustrates a partial cut-away sectionview of the adapter depicted in FIG. 30, illustrate flared grooves 129,which are adapted to receive ridges 120 of latch 104. The flare assistsin enabling the ridges 120 to be received into grooves 122. In thisembodiment, the adapter does not have the fast acting non-jamming spiralthreads 118, depicted in the adapter design illustrated in FIG. 27.

The adapter 102 has a rim 124 which is designed to engage with the rim126 of the Luer lock 100 to hold the two snugly together.

The embodiments of the invention depicted in FIGS. 26 to 31 have anumber of advantages:

1. The preferred embodiment allows for universal coupling with all Luerlock needle connections.

2. Needle interchangeability during use of the syringe is possible, thatis, different needles can be used for filling the vial and for injectingthe patient.

3. The needle platform (adapter) design allows for compatibility of thesyringe with other custom design needles or any subsequent needledesign, merely by altering the outer needle connection configurationplatform.

4. The syringe hub can be permanently closed after use of the syringe byscrewing on the broken plunger stalk after withdrawal of the needle intothe barrel.

5. The novel coupling mechanism between the platform and the plungerallows full axial movement of the plunger without the possibility of aninadvertent locking. But deliberate rotational action permits locking ofthe coupling device and withdrawal of the platform (adapter) with theattached needle in the barrel.

FIG. 32 illustrates a side elevation partial side section view of anembodiment of the invention related to that illustrated in FIGS. 26 to30. The embodiment depicted in FIG. 32 shows an adapter 130 whichextends partially from the front end of the barrel 132. A standard Luerlock 134 is formed in the front end of the barrel 132. The Luer lock hasa standard right hand thread 135. The barrel 132 has a left hand thread137 to release the adapter 130 for withdrawal inside the barrel 132,after the syringe is used. A needle hub 136 carrying needle 140 fits onthe tapered front end of adapter 130 and screws into the right handthread of the Luer lock 134. A given clearance 138 permits the needlehub 136 to be withdrawn into the interior of the barrel 132 after theadapter 130, hub 136, and needle 140 are unscrewed and withdrawn intothe barrel 132 by rotation of the plunger and engagement of the plungeradapter connection mechanism. As described previously, a Luer tip may bea simple conical device which accepts the needle base. This design couldalso be used in this embodiment, thus eliminating the screw connectionof the needle hub 136 and the Luer lock thread 135.

One advantage of the syringe design depicted in FIG. 32 is that theadapter 130, allows for longer needles to be accommodated. Anotheradvantage is that by reducing the minimum diameter of the platformneedle combination, a thinner barrel can be manufactured. For a givencapacity of syringe, this will allow the length of the syringe to belonger and therefore a longer needle to be accommodated within it. Byplacing the Luer lock threads in the barrel of the syringe rather thanon the platform, the outer diameter of the platform needle combinationis defined by the width of the needle hub and not by the supportingouter plastic Luer lock mechanism. It is therefore possible to ensure aslong a barrel as possible for a given capacity. The standard 3 ccsyringe represents a main portion of the syringe market. A standard 3 ccsyringe is often used with a 11/2 inch needle for intramuscularinjection. Accordingly, the barrel of a 3 cc syringe should be at least21/2 inches long to accommodate the withdrawn needle, adapter andplunger connector all within the barrel. This is done by the design asshown in FIG. 32.

The foregoing embodiments discuss various means of enabling the plungerto be connected securely to the hub 100 of the needle 2 in FIG. 26, forexample, to enable the plunger 16, when withdrawn, to pull the hub 6 andneedle 2 into the interior of the barrel S. In some versions includingthe adapter, the adapter disengages if it (the plunger connector) istwisted in the wrong direction. This provides an over tightening safetyfeature. The adapter is released from the syringe if the correctrotation is used. It will be recognized that these are illustrative ofspecific embodiments and there are other possible ways to make a secureconnection for the purpose of withdrawing the hub and needle into theinterior of the barrel.

FIG. 33 shows a perspective view partially in phantom of anotherembodiment of a safety syringe which includes a plunger 154 within abarrel 152. The syringe additionally includes a needle hub 156 carryinga needle 155 which may be covered by a needle guard 151 that is affixedto the barrel by way of barrel threads 153 and the complementary threadsof the guard.

As more clearly seen in the side elevation partial sectional view inFIG. 34, the plunger includes a circular cylindrical portion 154a havinga threaded end portion 154b, a finger press plate 154c and an outerannular ridge 154d for providing a sealing engagement with groove 152aof barrel 152. The plunger additionally includes portion 154e forengaging the needle adapter 150 as well as the plunger bung 157.

The plunger 154 additionally includes a narrowed portion 154f includinga weakened break point 154g, as well as a pair of resilient arms orprongs 154h. The details of these elements will become more apparentfrom a review of the expanded detailed drawings of FIGS. 41 and 42, forexample.

Returning to the syringe as illustrated in FIG. 34, it will be notedthat once sterilized and assembled as illustrated with the needle guardin place forming a sealing engagement with the threaded barrel, as wellas with the plunger in the position shown forming a sealing engagementbetween elements 152a and 154d, the interior of the structure is sealedat both ends, thus maintaining sterile conditions. As to forming andmaintaining the above noted seals, it will be recognized that otherforms of seals may be used. For example, although the exemplaryembodiment illustrated in FIG. 34 includes a threaded connection betweenthe needle guard and the end of the barrel, other forms of sealingarrangements involving friction fits or the use of annular ridges andcomplementary grooves, as well as other sealing connections asillustrated in previous embodiments, may also be used. In this regard,however, it will be noted that the threads 153 of the barrel are notonly designed to accommodate a threaded connection with needle guard151, but are also sized and designed to accommodate a threadedconnection with complementary threads 154b of the hollow plunger portion154a once this plunger portion is broken away and connected to the endof the barrel, as illustrated in FIGS. 38 and 39. Accordingly, anychange in the connection elements of 151 and 152, as previouslysuggested, would require a corresponding change in the manner ofconnecting elements 152 and 154a.

Again returning to the embodiment as illustrated in FIG. 34, consideredalong with the enlarged element details illustrated in FIG. 40, it isevident that adapter 150 is connectable to plunger portion 154e by wayof complementary surfaces 150a and 154i, as well as surfaces 150d and154k. As may be seen from a consideration of FIG. 40, all of thesesurfaces engage when the plunger is fully inserted and due to the slopesof the surfaces produces only a unidirectional torque on the adapterwhen the plunger is rotated in the proper direction. Plunger rotation inthe opposite direction causes surfaces 150d and 154k to separate and theplunger to be partially withdrawn. In operation withdrawal of theplunger and the attached bung 157 away from the adapter 150 isaccomplished with relative ease since the adapter is securely attachedto the barrel 152 by way of complementary threads 150b and 152b, as maybe seen from a consideration of FIGS. 35 and 37. Adding to the ease ofseparation of the adapter and plunger-bung is the relatively large slopeof the thread surfaces 150a and 154i which offer little or no resistanceto separation. Moreover, although the resilient ridge 154j and groove150c (FIG. 40) offer some resistance to separation, the combination doesnot prevent such separation or require more than a reasonable force to"unsnap" the connection when the adapter is affixed to the barrel. Ridge154j may be partially or wholly annular as one manner of decreasing orincreasing resistance to separation.

After use and with the adapter and plunger connected as illustrated inFIG. 34, the plunger may be rotated in the manner shown in FIG. 36 so asto disconnect the adapter from the interior threads at the distal end ofthe barrel by operation of the flat axial surfaces 150d and 154k. Animportant feature of this engagement mechanism is that once the adapterhas been disconnected at its threaded connection with the barrel, italong with the remainder of the needle assembly remain attached to theplunger portion 154e through the snap connection formed by ridge 154jand groove 150c. Thereafter, the plunger and attached needle assemblymay be withdrawn into the barrel in the manner illustrated in FIG. 37.

Clearly, retraction of the contaminated needle into the barrel preventsor substantially reduces the possibility of inadvertent needle stickinjuries. Furthermore, as may be appreciated from a consideration of theconnection illustrated in FIG. 40, it is another important feature ofthe engagement mechanism that once the adapter 150 has been disconnectedfrom the distal end of the barrel 152, in the absence of extraordinarymeasures or the use of a special tool, the needle assembly and theadapter cannot be reassembled to the barrel and be reused. Thus,attempts to reattach the adapter to the barrel for subsequent use,illicit or otherwise, is effectively prevented since the spiral groovesand faces of the adapter-plunger connection are shaped in such a manneras to prevent adequate transfer of torque in the proper direction toattain reattachment of the adapter to the barrel by merely rotating theplunger in the direction opposite that illustrated in FIG. 36.

In use, the exemplary embodiment of syringes as illustrated in FIGS. 33through 42 are bulk packaged, sterilized, assembled structures of thenature generally illustrated in FIG. 34. Initially, the needle guard 151is removed, the plunger and attached bung are withdrawn, and the properdosage of fluid within the syringe body is adjusted using calibrationmarkings (not shown) on the barrel in combination with the straightradial forward edge of the bung 157 to obtain a rapid and highlyaccurate measured reading of the contents. In this regard it must benoted that on conventional syringes the calibration markings, as well asthe bung are usually black, with the bung attached to a slightly opaqueplunger that is normally of an X cross-section. Additionally, theleading edge of the bung is normally curved outwardly. Accordingly,neither rapid nor accurate readings are obtainable with such structurewhich includes two interfaces between the bung and the fluid contentsand between the bung and the plunger. Such readings are additionallycomplicated by attempting to distinguish black calibration markingsagainst a black bung.

As previously noted, the forward surface of the bung 157 albeit annularis straight in the radial direction. Moreover, the coloration of thebung and plunger elements are the same so as to obtain a singleinterface. Moreover, the colors of the materials, as well as thecalibration markings, are selected to be contrasting so as tosignificantly improve the accuracy as well as the speed with whichmeasurements may be taken. As an additional important feature pertainingto rapid and accurate measurements, the cylindrical plunger portion 154ais sized to be closely received in barrel 152, thus reducing diffractionand increasing visibility.

Presuming that the syringe has been used to inject fluid, the plunger isrotated in the manner shown in FIG. 36 and the plunger as well as theneedle assembly including adapter 150 are withdrawn to the positionillustrated in FIG. 37 where the ends of the resilient arms 154hregister with annular groove 152a so as to retain the needle assemblyand lower portion of the plunger in the position illustrated.

Thereafter, cylindrical plunger portion 154a may be broken away at theplunger break point 154g in the manner illustrated in FIG. 38. Regardingthe narrowed portion of the plunger 154f, it is to be noted thatalthough illustrated as being circular in cross section in FIG. 41, itmay also take other shapes such as oval in order to enhance the easewith which portion 154a may be broken away.

After portion 154a has been broken away, it may be attached to thethreaded distal end of the barrel in the manner illustrated in FIG. 39.

Thus, subsequent to the intended use the needle assembly has beenwithdrawn into the barrel and locked in position by way of locking arm154h, for example.

Moreover, the bung and the raised edge of plunger portion 154e wouldserve to seal one end of the barrel, whereas portion 154a of the plungermay be attached to the threaded end of the barrel 152 by way of theillustrated threaded connection or by other well known snap-fit orfriction-fit connections, for example. As illustrated in FIG. 39, notonly is the needle withdrawn to a position eliminating inadvertentneedle sticks, but the barrel is sealed at both ends thus effectivelypreventing the escape of any toxic or contagious contents' a feature notseen in the known prior art.

As illustrated in FIGS. 33-39, the cylindrical plunger portion 154aconstitutes a hollow cylindrical sleeve closed at its inner end by thenarrowed portion 154f and open at its outer end terminating in thethreads 154b. As a consequence, when the plunger portion 154a isdisposed on the distal end of the barrel sealing the latter, theinterior of portion 154a serves as a reservoir or receptacle open at itsproximal end to the barrel of the syringe. Thus, in the unlikely eventthat the needle is not withdrawn the full distance, as illustrated inFIGS. 37-39, or should the adapter and needle be pushed axially inwardlyalong the barrel when the syringe is being handled or otherwisedisposed, e.g., by other disposable bearing on the exposed end of theportion of the plunger left in the barrel, there is no danger that theneedle can be pushed through the barrel or plunger or is otherwiseexposed.

As will be appreciated by the artisan, the selection of materials,coloring, shapes, as well as the location and nature of the seals, usedin the embodiment of FIG. 34, for example, may also find use in otherdisclosed embodiments. Moreover, it will also be appreciated by theartisan viewing the details of the embodiment of FIG. 34, for example,that since plunger element 154a is hollow and is made sufficiently longas to encapsulate the needle assembly in the position illustrated inFIG. 34, for example, should the adapter 150 malfunction and fail toseparate from the barrel, the exposed needle assembly may neverthelessbe covered by either needle guard 151 or by plunger portion 154a. Inthis regard it is to be noted that since the needle guard, as well asthe hollow plunger portion, have been made of approximately the samediameter as the threaded end of the barrel, both the needle guard andthe plunger portion 154a may more safely be installed on the exposedneedle in comparison with needle guards of smaller diameter such as isfound in the embodiment of FIG. 32. Accordingly, it will be seen thatthe design of the embodiment found in FIGS. 33 through 42 includesredundancy features whereby even if the needle assembly fails todisengage and retract after use, it may nevertheless be covered in atleast two other ways as discussed above, thus incorporating additionalsafety features,

A still further embodiment, which is the presently preferred embodiment,is illustrated in FIGS. 43 through 47. This exemplary embodiment issimilar in many respects to the previously recited embodiment as may beappreciated from a comparison of FIGS. 34 and 43. That is to say, barrel162 of FIG. 43 is substantially identical to barrel 152 of the previousembodiment except for the elimination of the seal-locking arrangementformed by members such as 152a and 154d and the inclusion of elements162a which, as illustrated in greater detail in FIG. 47, include twoannular ridges and an intervening groove on the inside surface at thefinger press end of the barrel. As will be seen in FIG. 47, the means162a of the barrel are designed to cooperate with annular ridge 164dincluded in plunger portion 164a. As will be recognized by the artisan,the parts can be reversed. That is to say, elements 162a can be includedon the plunger and element 164d can be included on the barrel. Theseelements cooperate when engaged to form an effective seal at one end ofthe barrel so as to prevent ingress or egress of materials to thecentral portion of the syringe body until it is used. This seal alongwith the use of a needle guard of the nature illustrated with theembodiment of FIG. 34, which may be affixed to the barrel 162 by way ofthreads 163, will completely seal both ends of the syringe body. Suchsealing, as with the previous embodiment, will allow the syringe to besterilized and then bulk packaged rather than individually packaged, butnevertheless retain internal sterility. Clearly, this feature willresult in beneficial results such as reduced labor and material costs.

Returning to a consideration of FIG. 43, it may be seen that barrel 162includes an annular groove formed at 162b which cooperates with theannular sealing ridge 160a included in adapter 160. This groove can beformed in the barrel during the manufacturing process or, preferably, isformed by the ridge 160a during assembly due to the resilience of theplastic barrel material. This sealing feature may be seen in greaterdetail in FIG. 46, wherein the sealing between the adapter and thebarrel is clearly enhanced. The embodiment of FIG. 43 additionallyincludes modifications to plunger portion 164e which is substantiallydifferent than that of portion 154a illustrated in FIG. 34. This plungerportion which is shown in greater detail in both FIGS. 44 and 45includes an outer circumferential lip 164h which is sufficiently reducedin diameter as to snap past barrel ridges 162a on assembly, but will beretained at the innermost ridge when the plunger and needle assembly arewithdrawn into the barrel. Such withdrawal occurs in the same manner aswas explained with regard to the embodiment of FIG. 34. That is to saythe coupling means between the adapter 160 and the plunger portion 164are of the same nature illustrated in FIG. 40, and the adapter isuncoupled from the barrel and withdrawn into it in the same manner aswas previously explained with regard to the embodiment of FIG. 34,except that means 162a are used to retain element 164e in the withdrawnposition.

Subsequent to withdrawing the plunger and needle assembly into thebarrel, the cylindrical plunger portion 164a may be broken away at thereduced break point or notch le4g of portion 164f. As with the previousembodiment, narrow portion 164f may be circular in cross section or haveother shapes such as oval for aiding in breaking away plunger portion164a.

After the plunger portion 164a has been removed, it may be joined to thedistal threaded end of barrel 162 as in the previously describedembodiment. As will be appreciated by the artisan, element 164 isdesigned to be attached to the distal barrel end, even if the adapterfails to disengage from the barrel and the needle fails to retract.Moreover, as with the embodiment of FIG. 34, those skilled in the artwill recognize that threaded connections such as formed at 163 and 164bmay be replaced with other connection means such as snap connections orfriction fits of the nature previously described.

Additionally, as with the previously described embodiment, the bung 157as well as the plunger portions may have similar coloration whichadditionally contrasts with the coloration of the calibration markings(not shown) on the barrel. Such coloration, as well as the radiallylinear forward surface 167a as detailed in FIG. 46, present a singlefluid plunger interface with greatly enhanced visibility as well asaccuracy for the reasons previously described.

Additionally, as with the previously described embodiment, due to thedesign of the adapter and plunger portion 164e and the connectionbetween them, the plunger may be fully compressed without permanentattachment between the elements. That is to say, elements 164j, whichmay be resilient prongs or a resilient annular ridge, maintain theconnection while engaged in groove 160c. As with the connection as shownin FIG. 40, the adapter when disconnected from the barrel is retained bythe plunger portion 164e when withdrawn into the barrel. However,elements 164j will release the engagement with the adapter when theplunger is withdrawn without rotation, since the adapter and barrelremain engaged.

As previously indicated, the artisan will appreciate that the beneficialfeatures of this embodiment, such as the coloration, sealing and lockingarrangements, among, others, may be adapted for use in still otherembodiments previously disclosed. For example, the embodiment of FIG. 32can obviously be modified to accommodate a full size needle guardconnected to the exterior of the barrel and may be further modified toinclude a sealing arrangement of the nature illustrated in either FIG.34 or FIG. 43 at the finger press end. Such modifications would resultin preventing the entrance of contaminating materials within the syringebody. Furthermore, the plunger portion containing the threadedconnection 2S illustrated in FIG. 32 can obviously be modified to be ofa hollow circular cylindrical form so as to be usable at the distal endof the syringe barrel whether or not the needle assembly has beenretracted into the barrel.

A further modification to the embodiment of FIG. 43 may be found in thefurther exemplary embodiment illustrated in FIGS. 48 through 50. Thisembodiment is similar in most respects to the embodiment of FIG. 43except that the narrowed intermediate portion of the plunger (164f and174f of the respective embodiments) includes as a substitute for thebreak point (164g) a connection means whereby the hollow cylindricalportion of the plunger may be unlatched or disconnected from the needleend portion and subsequently re-attached thereto. Such constructionallows the hollow finger press portion of the plunger 174a to be used asa needle guard both before and after use, as well as a plunger portionduring use.

As may be seen from a consideration of FIGS. 43 and 48, the needle endplunger portions (164e and 174e, respectively) are substantially thesame except that the narrowed intermediate portion 164f with break point164g has been replaced with a rectilinear locking mechanism 174f havinga rectangular shaped socket 1741 with two resilient wings or side arms174m that are slightly flared in the outward or radial direction.

The upper ends of these two arms include lips 174n which are arcuate andwhich have an internal groove 174o which is also arcuate.

The plunger portion 174a as in the embodiment of FIG. 43 is a hollowcylindrical cylinder in cross section. However, the needle end portionthereof has been modified as illustrated in FIGS. 48 and 49 to include arectilinear portion 174k which is complementary to the rectilinearportion 174f. Accordingly, when these portions are joined, both portions174a and 174e will rotate as a unit. Moreover, since the adapter/plungerengagement structure in this embodiment is the same as that found in theembodiment of FIG. 43, for example, unidirectional rotation of theadapter will be obtained in the previously described manner when theplunger is rotated.

As will be further noted from a comparison of FIGS. 43 and 49, forexample, the same type of sealing at the finger press end of the syringecomprising complementary ridge arrangements are included in theembodiment of FIGS. 48 through 50. It will be noted, however, that thefinger press end of the barrel 172 has been tapered so as to allow thearms 174m to flare outwardly and unlock or disengage from thecomplementary grooves included in plunger portion 174a.

In operation the sterilized syringe is supplied with cylindrical portion174aconnected over the needle and in sealing engagement with the distalend of the barrel 172. In this regard, although the sealing engagementis illustrated as a threaded connection, other connection means aspreviously described may be used. As supplied, the syringe would alsoinclude the adapter and needle assembly connected to the distal end ofthe barrel but with the plunger portions 174e and 174f along with bung17 withdrawn into the barrel and in sealing engagement with the fingerpress end of the barrel in the same manner noted with regard to theembodiment of FIG. 43. Additionally, arms 174m would be positioned asillustrated in FIG. 49. Accordingly, as supplied, both ends of thesyringe would be sealed, thus maintaining sterility as to the enclosedportions of the syringe body. Additionally, once the syringe is used theneedle end portion of the plunger along with the adapter and needleassembly may be withdrawn and plunger portion 174a disconnected, asillustrated in FIG. 49. Thereafter, the disconnected plunger portion174a may be reconnected as before to the distal needle end portion ofthe barrel so that both ends of the syringe are again sealed wherebytoxic or contagious material within the syringe body cannot escape.Moreover, as with the embodiment illustrated in FIG. 43, plunger portion174a may be re-attached to the barrel as a needle guard whether or notthe needle assembly has been withdrawn into the barrel.

Clearly the modification illustrated in FIGS. 48 through 50 offers theadvantage whereby a single element (174a) may be used both as a needleguard and as a portion of the plunger through the use of the disclosedrectilinear locking mechanism. Moreover, the previously describedsealing and locking arrangements and their beneficial results may bemaintained. Additionally, the previously described beneficial results tobe obtained by the shape and coloration of the elements wherebyvisibility and accuracy of measurement of the syringe fluid contents mayalso be applied to the embodiment of FIGS. 48 through 50. Furthermore,the artisan will appreciate that the beneficial feature of thisembodiment may be adapted for use in still other embodiments previouslydisclosed.

As will be recalled, a further feature of the present invention providesfor a venting structure in the adapter for venting air from the interiorof the barrel once the barrel has been substantially filled with fluidto be injected and prior to injection. It will be appreciated that inthose embodiments hereof where the hub or adapter has structure whichprotrudes into the barrel from the distal end of the barrel, there isformed an annular space between such protrusion and the barrel.--Withthe central passage through the adapter and needle terminating inwardlyof the distal end of the barrel, there is the danger of entrapment ofair within the annular space between the protrusion and the barreladjacent the distal end of the barrel. The following is a description ofa specific embodiment of the present invention which eliminates any suchair and vents the entirety of the air in the barrel prior to injection.The concept and structure of this embodiment are applicable to theprevious embodiments, for example, to the hub 6 of the embodiments ofFIGS. 5, 8, 10, 15 and 17, the adapter 102 of the embodiments of FIGS.26-32 and the adapter 150 of the embodiments of FIGS. 33-42, and theadapter 160 of the embodiment of FIG. 43.

Turning now to FIG. 51, there is illustrated an adapter 200substantially identical to the adapter illustrated in FIG. 40, with thefurther improvement of the vent openings, as will now be described.Adapter 200, of course, has a central axial passageway 202 defined inpart by the protrusion '204 of the adapter into the barrel and on whichprotrusion is mounted the spiral threads or surfaces 206, terminating inthe annular groove 208, all as previously described. Adapter 200 isthreaded into the end of the barrel, as illustrated in FIG. 52,similarly as the embodiment of FIG. 40.

In this form, however, there is provided at least one and preferably apair of vent passages 210 extending radially from and in communicationwith the central axial passageway 202. These passages preferably extendin grooved portions 212 formed in the face of the flange facing theproximal end of the barrel. Additionally, that face is tapered radiallyinwardly in a direction toward the needle end of the barrel, forexample, on the order of about 3°. Further, an annular trough or groove211 is preferably formed in the tapered flange face about the base ofprotrusion 204. Groove 211 lies in communication with grooved portions212 and vent passages 210. One or more additional annular grooves mayalso be provided including about the outer margin of the tapered flangebase or at intermediate radial positions. By grooving the passagewayportions 210 and groove(s) 211 in the face of the adapter 200 andtapering that face, the grooves 211, 212 and passage portions 210 willassume the most superior position within the interior of the barrel whenthe syringe is oriented vertically with the needle uppermost.Consequently, when the plunger is advanced toward the needle end to ventair from the interior of the barrel, any air trapped within the annularspace 214 between the distal end of the barrel and protrusion 204 willvent through the grooves and openings into the central passageway.Hence, the interior of the barrel may be purged of any air prior toinjection. It will be appreciated that there may be only a single ventpassage 210, although preferably at least two such passagesdiametrically opposed to one another are provided. More than two suchpassages may also be provided, preferably equally spaced about the axisof the adapter.

Referring now to the embodiment of FIG. 53, the central passageway 202aterminates short of the distal end of the protrusion 204a. Consequently,the central passage 202a communicates only with the one or more radiallyextending passages 210a and grooves 211a, 212a. In this form, not onlydo the passageway portions 210a and grooves 211a, 212a form the superiorpositions when the syringe is oriented vertically with the needleuppermost to enable venting air from the barrel and particularly theannular space 214a between the barrel and protrusion 204a, but providethe sole passageway portions for egress of fluid from the interior ofthe barrel through the central passageway 202a during injection. Theopening 216 in the end of protrusion 204a is in the form of amulti-sided opening, e.g., a hex-shaped opening, for purposes ofreceiving a tool for assembling the syringe. Thus, a tool may beinserted through the opposite end of the barrel and received in opening216 to thread the adapter onto the barrel.

Referring now to the embodiments of the invention illustrated in FIGS.54-56, three forms of syringes having tamperproof features aredisclosed, respectively. In FIG. 54, there is illustrated a syringehaving a barrel 300, a finger press 302 for the plunger, and a needleguard 304. The needle guard is, of course, screw-threaded or otherwisesecured to the end of the barrel 300, for example, as illustrated inFIGS. 33 and 34. In this form of the invention, a strip 306 of paper orother material, such as plastic, having adhesive along one side thereofis applied along a side of the syringe. Particularly, the strip isapplied along the side of the barrel 300 and onto the end of the needleguard 304 at its juncture with the barrel 300. The opposite end of thestrip 306 is applied to the finger press 302 and preferably extendsacross the top of the finger press and partially down the opposite sideto at least the cylindrical barrel portion. In this manner, the juncturebetween the finger press 302 and barrel is spanned by at least a portionof the strip 306. As a result, it will be appreciated that anyinadvertent or attempted removal of the needle guard from the barrel orrotational or axial movement of the finger press 302 relative to thebarrel will cause the strip 306 to tear or become twisted whereby thedisruption of the seal at these junctures and possible tampering withthe syringe will be indicated.

In FIG. 55, another form of tamperproof syringe is disclosed. In theembodiment illustrated in FIG. 55, the barrel, finger press and needleguard are indicated as in FIG. 54 with the suffix "a" applied thereto.In this form, thin-film plastic material 308 and 310, respectively, isapplied, for example, by heat-shrinking, about each of the juncturesbetween the needle guard 304a and barrel 300a on the one hand and thebarrel 300a and finger press and plunger portion 302a, on the otherhand. Once again, any rotary movement or other movement of the needleguard 304a relative to barrel 300a or rotary or axial movement of thefinger press 302a relative to barrel 300a will be detected by thesevering of the shrink-wrapped plastic material or its wrinkling wherebydisruption of the seals at the opposite ends of the syringe or tamperingwith the syringe will be indicated. It will also be appreciated that theshrink-wrap of plastic material assists in maintaining the sterility ofthe syringe and that suitable tear strips may be provided along each ofthe shrink-wrapped portions to facilitate their removal and use of thesyringe.

In FIG. 56, the like elements of the syringe are illustrated by likereference numerals as in FIGS. 54 and 55, followed by the suffix "b". Inthis form, the syringe is dipped into a melted plastic material wherebya thin-film coating of plastic 312 is applied about and completelyenvelops the syringe with the needle guard attached and plunger locatedin its axially innermost position. For example, the plastic coat 312 maycomprise a clear chlorinated polyvinyl chloride coating (CPCV). Theingredients are vinyl chloride-vinyl acetate resin silicon dioxide(amorphus) with a methol isobutyl ketone base. This is an air drycoating. The drying can be accelerated by raising the temperature to100° F. The melting temperature of the plastic material is, of course,less than the melting temperature of the plastic forming the syringe,and it will be appreciated that a clear plastic material should be usedsuch that the gradations and other information on the syringe may bevisualized through the thin-film plastic coating. Thus, any efforts toremove the needle guard 304b or displace the plunger will be immediatelydetectable by the break in the thin-film 12 of plastic material, henceindicating disruption of or tampering with the seals adjacent theopposite ends of the syringe. The coating material is, of course,sufficiently thin to enable the needle guard to be readily removed fromthe barrel and the plunger to be readily rotated to break the seal,hence permitting axial movement of the plunger relative to the barrel.Therefore, the plastic coating can be left on the syringe barrel duringuse, eliminating the need to physically strip it from the barrel anddispose of it separately.

With respect to each of the tamperproof configurations illustrated inFIGS. 54, 55 and 56, respectively, the tamperproof features may also beprovided with integral indicators which change color or become visibleafter exposure to sterilizing radiation. Thus, the strip 306 of FIG. 54,the thin-film plastic material 308 and 310 of FIG. 55 and the hot meltedplastic coat 312 of FIG. 56 may be provided with integral sterilizingradiation indicators such as ethylene oxide or other sterilizing agentswhich change color or become visible after exposure to sterilizingradiation. Consequently, not only can it be determined at the point ofuse of the syringe that the syringe has not been tampered with but alsothere is assurance by the change of color or visibility of theindicators that the syringe has been sterilized.

Referring now to the embodiments hereof illustrated in FIGS. 57, 58 and59, the barrel, plunger, and adapter are formed similarly as in previousembodiments, for example, as in the preferred embodiment hereofillustrated in FIGS. 3340 using the adapter illustrated in FIGS. 51-53.The syringe is illustrated in FIG. 57 prior to use and before a ferrulewith attached needle, e.g., as illustrated in FIGS. 33 and 48, isattached to the adapter. In this form, there is provided an end cap 400having female threads for threadedly engaging corresponding male threadson the distal end of the barrel, for example, the male threads at thebarrel end illustrated in FIGS. 33 and 48. In the previous embodiments,for example, with reference to FIGS. 35-39, upon withdrawal of theadapter and needle within the barrel, the proximal end of the plungermay be broken off and reapplied to the distal end of the barrel byscrew-threading the plunger and barrel to one another. There is,however, the psychologically discomforting possibility of contacting anindividual's hand with the barrel end, notwithstanding the withdrawal ofthe needle into the barrel, prior to the threaded attachment of theproximal plunger end portion to the distal end of the barrel.Consequently, for those syringes wherein the adapter carries a Luer lockmale fitting which releasably receives the ferrule of the needle, i.e.,the needle is not directly or integrally attached with the adapter, thesyringe may be provided as illustrated in FIG. 57 with a cap 400screw-threaded on the distal end of the barrel. As illustrated, the cap400 has a flat external surface 402 opposite the otherwise open end ofthe cap.

In FIG. 58, the cap 400a is similarly provided with internal femalethreads at its open end for connection with the male threads at thedistal end of the barrel. The closed opposite end of the cap 400a,however, has feathered edges 404 in conjunction with a concavity orrecessed face 406 in the central portion of cap 400a.

A further form of cap is illustrated in FIG. 59. In FIG. 59, cap 400bhas, as indicated previously, internal female threads about its open endfor threadedly engaging the male threads on the end of the barrel. Atits closed end, there is provided a ring 408, the outer surface 410 ofwhich carries an adhesive, preferably a pressure-sensitive adhesive.Ring 408 may have adhesive along its opposite side for adhesivelysecuring it to the closed end of barrel 400b. A release membrane orpaper portion 412b may be provided along the outer surface of the ringoverlying and protecting the pressure-sensitive adhesive 410.

Referring now to drawing FIG. 59A, there is illustrated a cap 400c whichmay comprise any one of the caps 400, 400a and 400b and which has thefeatures described with respect to those caps. In addition, the cap 400cincludes a flexible hinge 414 which connects the cap to the body of thebarrel of the syringe, it being appreciated that other types of hingesmay be employed. Various methods may be used to connect the hinge to thesyringe barrel, for example, the distal end of the hinge 414 maycomprise a ring or band 416 disposed about the cylindrical syringebarrel. As a consequence of this construction, the cap remainsintegrally attached to the syringe and is thus readily available afterthe syringe has been used to close the open and possibly contaminatedend of the syringe barrel. Additionally, the cap and barrel or band orring surrounding the barrel may have parts cooperating with one anotherto retain the cap 414 in a position which does not interfere with thenormal usage of the syringe, i.e., when the needle projects from thesyringe barrel end. To accomplish that, the barrel or the band or ringabout the barrel and the cap may have cooperable releasable elements.For example, the band and cap may have Velcro™ securements or areas ofadhesive or mechanical interconnections such as a snap-fit, i.e., a pinand recess, so that the cap may be releasably retained in anon-interfering position as illustrated by the dashed lines.

Referring now to FIGS. 60-62, the use of the caps illustrated in FIGS.57-59 will be described in conjunction with the illustrated use of thecap 58. Instead of passing the proximal plunger end portion broken fromthe plunger, as illustrated in FIGS. 34, 25a-25c, 38, 39 or 49, in frontof the barrel for connection therewith or passing the user's hands orarms adjacent the barrel end after use of the syringe, a cap 400, 400aor 400b may be placed on a table or other flat surface with its open endfacing upwardly. Note that once the cap is removed from the syringeprior to use, the cap is not contaminated by any body fluids. After use,the syringe may be applied to the cap. Thus, as illustrated in FIG. 60,the proximal end of the plunger may be broken from the plunger barrel,leaving that end of the barrel sealed by the plunger bung. Instead ofapplying the broken-off plunger end to the distal end of the barrel, itmay be discarded and the distal end of the barrel may be applied to thecap. Particularly, by inserting the distal end of the barrel into theopen end of the cap and exerting downward pressure on the barrel, thefirst few threads of the barrel may ratchet past the female threads onthe cap to engage the barrel and cap one to the other. Note that theuser's hand or arm need not pass in front of the possibly contaminatedbarrel end in order to close the barrel end with the needle retractedinto the barrel.

While this axial engagement of the barrel with the cap may be sufficientto secure and seal the barrel end, the barrel is preferably rotatedrelative to the cap to ensure a tight, snug sealing fit between thebarrel and cap. When using the flat-ended cap 400 illustrated in FIG. 7,the cap, after its initial securement to the barrel end, may be graspedand rotated relative to the barrel. Alternatively, when using the capillustrated in FIG. 58, the downward pressure of the barrel on thefeathered edges 404 of the cap causes the cap to displace air betweenits recessed, closed end 406 and the flat surface whereby the cap servesas a suction cup releasably adhering the cap to the surface.Consequently, once the barrel has been applied to the cap, the barrelmay be rotated with the suction effect tending to maintain the capagainst rotation on the flat surface. Also, the suction effect preventsthe cap from sliding laterally along the flat is surface. Once thebarrel and cap are secured one to the other by downward pressure andrelative rotation, a slight rocking motion, as illustrated in FIG. 62,will dislodge the cap from the flat surface and break its suction griptherewith.

In the embodiment illustrated in FIG. 59, the cap 400b may have releasepaper 410 on the annular ring 408. By removing the release paper andreleasably adhesively securing the cap 400b to the flat surface, thebarrel can be applied thereto and rotated relative to the cap similarlyas with the embodiment of FIG. 58. The rocking motion illustrated inFIG. 62 will also release the adhesive from the surface whereby thesyringe with its capped and sealed end may be removed from the adjoiningsurface. Also in FIG. 59, it will be appreciated that the annular ring408 may comprise a disk or discrete areas of adhesive. Further, insteadof release paper, the plastic tamperproof packaging illustrated in FIGS.54 to 56 may be used. For example, the strip of paper or other materialillustrated in FIG. 54 may be enlarged at the lower end to overlie thepressure-sensitive adhesive such that the paper wrap or shrink wrapwhich affords a tamperproof feature may also serve as the release paperfor the adhesive. The shrink wrap of FIG. 55 may also be employed as therelease paper for the embodiment hereof illustrated in FIG. 59, theshrink wrap being illustrated in FIG. 59 at 412 and the portion thereofoverlying the adhesive illustrated at 412b.

Of course, the embodiment illustrated in FIG. 59A is used similarly aspreviously described with respect to the caps of FIGS. 57-59. In theembodiment of FIG. 59A, however, the cap is releasably retained in anon-interfering position and may be readily displaced from that positionto the syringe barrel closed position.

Referring now to the embodiment hereof illustrated in FIGS. 63 and 64,it is advantageous to preclude the needle from exposure after use,whereby the risk of needle stick injury may be entirely avoided. Thatis, if the needle can be removed from the injection site and into thebarrel without exposing the thus contaminated needle, the risk of needlestick injury is substantially prevented.

In this embodiment of the invention, the syringe is virtually identicalapart from the distal end of the barrel. In this form, the distal end ofthe barrel is elongated as illustrated at 500 in FIG. 63. The elongatedend portion 50 of the barrel may be externally threaded to receive thecap of the previous embodiment or the female threads at the opposite endof the plunger once the latter is broken from the syringe as previouslydescribed. Also, while the needle 502 in this embodiment is illustratedas integrally attached to the adapter 504 (which may take the form ofany one of the adapters previously described), the adapter may beprovided with the Luer tip for receiving the hub of a standard Luerneedle. In both cases, the end of the adapter or the hub of the Luerneedle is recessed within and lies short of the end of the elongatedbarrel end portion 500. Only the needle 502 or a portion thereof isexposed through the barrel end.

With this arrangement and as illustrated in FIGS. 63 and 64, the needlepenetrates the injection site, i.e., the individual's skin Sk. The endof the barrel is also brought into engagement with the skin as theneedle penetrates further into the skin, as illustrated in FIG. 63. Theplunger is then depressed, injecting the fluid through the needle intothe individual. Following the injection and with the barrel end of thesyringe still pressed against the skin, the plunger is rotated andcoupled with the adapter, as previously described, and the adapter withthe needle is withdrawn with the plunger within the barrel, asillustrated in FIG. 64. In this manner, the contaminated needle is neverexposed to the risk of needle stick injury. After the barrel is removedfrom the skin, the cap or the broken plunger portion may be secured andseated to the elongated barrel end as previously described.

Referring now to the embodiment hereof illustrated in FIGS. 65-69, thereis illustrated a syringe barrel 600 carrying an adapter 602screw-threaded at 604 into the distal end of the barrel 600. The adapter602 includes a Luer fit 606 for mounting the hub 608 of a needle, notshown in this drawing figure. Note in the drawing figures, the annularridges 617 projecting from the forward face of the adapter along theinside face of the annular shoulder at the distal end of the barrel.These ridges assist in performing a sealing function when the adapter isscrew-threaded into the distal end of the barrel. A plunger 610 ismounted for axial movement within the barrel and includes a bung 612 atits distal end in sealing engagement along the interior side walls ofthe syringe barrel. The plunger is, of course, mounted for axial slidingmovement within the syringe barrel for injecting fluid from within thebarrel through the adapter and Luer fit into and through the needle andfor drawing fluid into the barrel, for example, from a vial, not shown.The bung is formed of a Santoprene compressible material and has aplurality of circumferentially extending ribs for forming sealingengagements with the interior walls of the barrel. The plunger 610includes at its distal end a central portion or projection 614 carryinga plurality of axially spaced ribs 616 for engaging and sealing withinterior wall surfaces of bung 612.

In this form of the invention, the central portion 614 includes anaxially extending male projection 615 having a plurality of discreteangularly related axially tapered sides or faces 618. In the illustratedform, the projection 618 is hexagonal in cross-sectional configuration,with the sides being tapered toward the distal end of the barrel. Spacedaxially from the tapered sides is a continuously circumferentiallyextending radially outwardly projecting rib 620 directly adjacent acontinuous circumferentially extending radially inwardly directed groove622. The surfaces 618, 620 and 622 comprise adapter engagement structuredisposed at the distal end of the plunger for engagement withcomplementary or mating engagement structure carried by the adapter.

The inner face of the adapter 602 is tapered toward the central axis ofthe adapter and has a recess 624 substantially complementary in shape tothe male projection 615 on the plunger. Specifically, the recess 624includes a plurality of tapered sides or faces 626 complementary inshape or taper to the faces 618, as well as a continuouscircumferentially extending radially inwardly directed rib 628 and acontinuous circumferentially extending radially outwardly projectinggroove 630.

The opposite end of the plunger 610 includes a radially outwardlyprojecting continuously circumferentially extending rib 634. A pair ofradially inwardly projecting ribs 636 and 638 are formed about the innersurface of the proximal end of the barrel defining a continuous radiallyoutwardly extending groove 640 therebetween.

In this form of the invention, it is desirable to permanently orirreversibly lock the plunger and the adapter to one another when theplunger is finally seated in its axially innermost position within thesyringe barrel such that the plunger and adapter act as a unit andcannot be axially disconnected one from the other. In this manner, theplunger and adapter can be locked permanently one to the other only withfirm positive axial pressure intentionally exerted on the plungerrelative to the barrel. This requires a deliberate strong axial force tobe applied to the plunger to effect the locking action. It also makes itunnecessary for the user to maintain forward axial pressure on theplunger when rotating the plunger to unthread the adapter from thebarrel. In use, the plunger is advanced toward the adapter such that theradially outwardly projecting rib 620 engages the inwardly projectingrib 628 on the adapter with the distal end of the plunger received inthe recess of the adapter, as illustrated in FIG. 66. The user is thusable to recognize from this initial engagement and hence initialresistance to further axial movement of the plunger relative to thebarrel that the plunger is just axially short of being finally seatedand locked relative to the adapter. At this time, the user is thussignalled that the plunger and adapter will be permanently locked to oneanother upon further axial displacement of the plunger relative to thebarrel. Upon such further forceful axial displacement and as illustratedin FIG. 67, the rib 620, due to the compressibility of the plasticmaterials principally of the plunger, slips past the rib 628 on theadapter and seats in the groove 630. Correspondingly, the radiallyinwardly directed rib 628 seats in the groove 622 of the adapter, thuspermanently locking the plunger and adapter to one another. As theplunger is axially advanced from its position short of the finallyseated position relative to the adapter, i.e., from the positionillustrated in FIG. 66 to that of FIG. 67, toward the distal end of thebarrel, the bung 612 compresses, as illustrated in FIG. 67. Thisensures, once the plunger and adapter are retracted into a finalposition within the barrel, a further effective sealing action at theopposite end of the barrel. With the rib and groove engagement of theplunger and adapter, the plunger may be rotated to unscrew the adapterfrom the distal end of the barrel. Thus, by withdrawing the plunger fromthe barrel, as illustrated in FIG. 68, the adapter and needle carriedthereby are withdrawn into the interior confines of the syringe barrel.By breaking the plunger off at its weakened portion, as previouslydescribed, the plunger may be threaded onto the distal end of thebarrel, as illustrated in FIG. 73. With the plunger bung sealing theopposite end of the barrel and the plunger threaded on the distal end ofthe barrel, the barrel is sealed at its opposite ends.

Referring to the embodiment hereof illustrated in FIGS. 69-71, likereference numerals as in the prior embodiment are applied to like parts,followed by the suffix "a." In this embodiment, the bung 612a isreleasably retained in a first axial position relative to the projectingportion 614a of the plunger as illustrated in FIGS. 69 and 70 and asecond axial position spaced from the first axial position, illustratedin FIG. 71. To accomplish this, the projecting portion 14a of theplunger end carries a plurality of radially outwardly projecting axiallyspaced flared ribs 650 whereas the interior surface of the bung 612acarries a plurality of axially spaced complementary shapedcircumferentially continuous tapered ribs 652. The ribs 650 and 652 areconfigured such that the complementary inclined surfaces thereof engageone another in the first or initial axially extended position of thebung 612a relative to the plunger, as illustrated in FIGS. 69 and 70. Asthe plunger is advanced to engage the ribs 620a and 628a to form theinitial stop position, the annular end wall surface of bung 612a engagesthe interior axial face of the adapter 602a. Upon firm pressure beingapplied to the plunger to displace it axially into its final seatedposition, as previously described, this forceful axial pressure enablesthe plunger to slide relative to the bung such that the complementaryinclined surfaces slide past one another and the radial surfaces of theprojections 650 and 652 engage one another, as illustrated in FIG. 71.Thus, once the plunger and adapter are permanently locked one to theother as illustrated in FIG. 71, the plunger and adapter can be jointlyrotated to unscrew the adapter from the barrel end for location of theadapter and needle carried thereby axially into the barrel, with theradial surfaces of the ribs 650 and 652 engaging one another to carryone the plunger bung axially with the plunger upon withdrawal of theplunger. Referring now to the embodiment hereof illustrated in FIG. 72,wherein like parts as in the prior embodiments are illustrated with likereference numerals, followed by the suffix "b," there is provided aplunger having, instead of a bung, a radially outwardly directed flange65g forming an interference fit with the interior wall of the barrel.The flange 658 is weakened at 660 to enable the flange to flex. Axiallybeyond the flange, the plunger includes the projecting portion 615bshaped similarly as previously described and complementary to the recess624b in the adapter. Once the plunger has been advanced such that theribs 620b and 628b initially engage one another, the flange bearsagainst the inner face of the adapter. When final locking is desired,the plunger is advanced forwardly into its permanently seated andlocking position relative to the adapter. The weakened portion 660 ofthe flange enables this final axial advancement of the plunger betweenthe initial and final seated positions with the flange deforming at itsweakened portion 660.

It will be appreciated that a reverse configuration of the male andfemale parts on the plunger and adapter, respectively, illustrated inFIGS. 65-72 may be employed, for example, with the type of plunger andadapter illustrated in FIG. 40. Thus, a radially outwardly projectingrib may be provided on the male projection of adapter 150 ahead ofgroove 150c. The initial engagement of the radially inwardly projectingrib 154 on the female end of the plunger with the radially outwardlyprojecting rib in advance of the groove 150c on adapter 150 provides theinitial resistance or stop to finally locking the plunger and adapter toone another. By further forceful axial pressure on the plunger, the ribsslip past one another to finally lock the adapter and plunger to oneanother. Of course, the reverse of this arrangement may likewise beused, i.e., the rib and groove being located on the plunger and only aradial outwardly directed rib being located on the adapter.

It will also be appreciated that other types of permanent lockingconnections may be provided between the plunger and adapter. Forexample, complementary sawtooth ribs may be provided with their inclinedsurfaces engaged to provide the initial resistance and being movablepast one another to engage the radial surfaces thereof to permanentlylock the adapter and plunger to one another. Further, it will beappreciated that either of the male or female latching structures of theplunger and adapter, as the case may be, can have one or more axiallyextending slits to facilitate relative axial movement of the plunger andadapter toward their permanently locked position and without detractingfrom the ability of the rib and groove (or complementary sawteeth) topermanently engage one another. Also, the ancillary features of thepresent invention described herein such as the air venting feature ofthe adapter illustrated in FIGS. 51-53, the tamperproof features ofFIGS. 54-56 and the cap arrangements of FIGS. 57-64 may be employed withthe permanent locking feature of the embodiment of FIGS. 65-77.

Referring now to FIGS. 78 and 79, there is illustrated an arrangement ofan adapter 700 and a plunger end 702 having a bung 704. The adapter 700and plunger end 702 are similar to the adapter and plunger endillustrated in FIG. 40, except that the adapter 700 has a female recess706 and the plunger end 702 has a male projection 708 generallycomplementary in shape to the female recess 706. That is, while theadapter and plunger end combination of FIG. 40 have the male and femaleparts on the adapter and plunger end, the adapter and plunger endillustrated in FIG. 78 have a reverse configuration and with similarlyfunctioning elements. Thus, adapter 700 has external threads 710 forthreaded engagement with the threads 712 (FIG. 79) at the barrel end ofthe syringe for sealing the barrel. The adapter flange 714 has agenerally frustoconical shallow recess 716 opening into the recess 706.The base of recess 706 is provided with teeth 718 which have flats 720and angled surfaces 722. Additionally, the recess 706 includes aprojecting annular rib 724.

The male projection 708 on plunger end 702 is shaped for reception inthe recess 706 and has complementary-shaped teeth 726. That is, teeth726 have flats 728 and angled surfaces 730 which engage the flats 720and angled surfaces 722 in the recess 706 of adapter 700 when theplunger is fully axially advanced in the syringe barrel. The maleprojection 708 also includes a radially inwardly directed annular groove732.

The cooperation of the teeth and the rib and groove are similar aspreviously described, particularly with respect to the embodiment ofFIG. 40. For example, when the plunger is advanced in the barrel toengage the projection 708 in recess 706, the engagement structureenables the plunger to rotate relative to the adapter and barrel tobring the flat surfaces 728 into alignment with the flats 720 of theadapter. Once aligned, joint rotation of the plunger and adapterunthreads the adapter from the end of the syringe barrel. It will beappreciated as illustrated in FIG. 79 that when the plunger is axiallyadvanced to its fullest extent, the rib 706 engages in the groove 732 toenable joint withdrawal of the plunger and adapter once the screwthreads 710 are disengaged from the barrel threads 720. Therib-and-groove arrangement may, of course, be reversed with the groovelocated on the adapter and the rib on the plunger.

A particular feature of this arrangement is that the cost of materialsfor forming the adapter is substantially reduced. The adapter ispreferably formed of a polycarbonate material and, by forming the femalerecess in the adapter, a significant reduction in material is achievedin comparison with the arrangement of the adapter illustrated in FIG. 4.Functionally, however, the cooperation of the male and female parts asillustrated in FIGS. 78 and 79 is the same as illustrated in FIG. 40.

It will be appreciated that the foregoing description and illustrationsdisclose a plunger which is cylindrical over the major portion of itslength. It will be appreciated, however, that the cross-sectionalconfiguration of the plunger may be other than cylindrical, at leastbetween the cooperating ridges and grooves 162 and 164 at the proximalend of the plunger and the rib on the bung which cooperates with thegroove in the distal barrel end when the adapter has been withdrawn toseal the proximal end of the barrel. Thus, the cross-sectionalconfiguration of the plunger need not be cylindrical but can becruciform, solid cylindrical, or only partly cylindrical, or any otherconfiguration whereby the opposite ends of the plunger are connected oneto the other and the plunger may be broken off as illustrated.

While the invention has been described in connection with what ispresently considered to be the most practical and preferred embodiment.it is to be understood that the invention is not to be limited to thedisclosed embodiment, but on the contrary, is intended to cover variousmodifications and equivalent arrangements included within the spirit andscope the appended claims.

What is claimed is:
 1. A syringe comprising:(a) a hollow, axiallyelongated barrel; (b) an adapter carried by said barrel adjacent adistal end thereof and removable therefrom in response to rotationrelative to said barrel, the adapter carrying a needle and providingfluid communication with the interior of said hollow barrel; (c) aplunger axially movable in said barrel between positions axially spacedfrom said adapter and engaging said adapter, said plunger having firstand second opposite ends; and (d) adapter engagement structure disposedat said first end of the plunger and engageable with a mating connectionengagement structure on the adapter, said structures having respectivedrive and connective engagement surfaces, said drive surfaces beingengageable with one another when said plunger lies in said adapterengaged position, said drive surfaces being jointly movable to enablerotation of the adapter relative to the barrel in response to relativerotation of the plunger and barrel to cause the adapter to part from thedistal end of the barrel, said connective surfaces (i) lying in axialopposition to and engaged with one another when said drive surfaces areengaged with one another to connect the plunger and adapter one with theother and (ii) enabling said adapter, when parted from the end of thebarrel in response to joint rotation of said adapter and said plungerrelative to said barrel, to be withdrawn with the needle into theinterior of the barrel in response to joint axial movement of saidplunger and said adapter in a direction away from the distal end of thebarrel.
 2. A syringe according to claim 1 wherein said second end ofsaid plunger has structure for connecting said plunger second end withstructure at the distal end of the barrel, rupturable structureintermediate said first and second ends of said plunger for detachablyconnecting said first and second ends of said plunger, whereby saidfirst and second ends of said plunger can be detached from one anotherwhen said adapter and needle are withdrawn into the interior of thebarrel, leaving said first end in said barrel, said second end beingattachable to said structure at the distal end of the barrel.
 3. Asyringe according to claim 1 wherein said adapter engagement andconnection engagement structures on said plunger and adapter,respectively, include alignment surfaces inclined to an axis of thebarrel and engageable with one another in response to axial movement ofsaid plunger toward said adapter causing relative rotation between saidplunger and said adapter.
 4. A syringe according to claim 3 wherein saidsecond end of said plunger has structure for connecting said plungersecond end with structure at the distal end of the barrel, rupturablestructure intermediate said first and second ends of said plunger fordetachably connecting said first and second ends of said plunger,whereby said first and second ends of said plunger can be detached fromone another when said adapter and needle are withdrawn into the interiorof the barrel, leaving said first end in said barrel, said second endbeing attachable to said structure at the distal end of the barrel.
 5. Asyringe comprising:a hollow, axially elongated barrel having distal andproximal ends; needle-mounting structure affixed to said distal end ofsaid barrel; a hollow needle releasably carried by said needle-mountingstructure and having an end in communication with the interior of saidbarrel; a plunger axially slidably received in said barrel through saidproximal end thereof and having a thumbpress at one end external to saidbarrel and a bung at an opposite end within the barrel engaging interiorwall portions of the barrel; an element carried by said opposite end ofsaid plunger and engageable with said needle mounting structure uponaxial sliding movement of said plunger toward said distal end of thebarrel; said element in engagement with said needle-mounting structureeffecting a breakaway of said needle-mounting structure from said huband withdrawal of said needle into the barrel in response to axialsliding movement of said plunger away from the distal end of the barrel.6. A syringe comprising:(a) a hollow, axially elongated barrel having ahollow interior; (b) an adapter carried by said barrel adjacent a distalend thereof and removable therefrom in response to rotation relative toand about the axis of said barrel, the adapter carrying a needle andproviding fluid communication with the interior of said hollow barrel;(c) a plunger axially movable in said barrel between positions axiallyspaced from said adapter and engaging said adapter, said plunger havingfirst and second opposite ends; and (d) adapter engagement structuredisposed at said first end of the plunger and engageable with a matingconnection engagement structure on the adapter, said structures havingrespective drive and connective engagement surfaces, said drive surfacesof each said adapter engagement structure and said mating connectionengagement structure extending radially and being spacedcircumferentially from one another about the axis of said barrel, saidcircumferentially spaced drive surfaces of said adapter engagementstructure engaging respective circumferentially spaced drive surfaces ofsaid mating connection engagement structure in response to relativerotation of said plunger and said adapter when said plunger lies in saidadapter engaged position, said drive surfaces being jointly movable toenable rotation of the adapter relative to the barrel in response torelative rotation of the plunger and barrel to cause the adapter to partfrom the distal end of the barrel, said connective surfaces (i) lying inaxial opposition to and engaged with one another when said plunger liesin said adapter engaged position to connect the plunger and adapter onewith the other and (ii) enabling said adapter, when parted from the endof the barrel in response to joint rotation of said adapter and saidplunger relative to said barrel, to be withdrawn with the needle intothe interior of the barrel in response to joint axial movement of saidplunger and said adapter in a direction away from the distal end of thebarrel.
 7. A syringe according to claim 6 wherein said plunger includesrupturable structure intermediate said first and second ends thereof fordetachably connecting said first and second ends relative to one anotherwhereby said second end can be detached from said first end when saidadapter and needle are withdrawn into the interior of the barrel.
 8. Asyringe according to claim 6 wherein said second end of said plunger hasstructure for connecting said plunger second end with structure adjacentthe distal end of the barrel, rupturable structure intermediate saidfirst and second ends of said plunger for detachably connecting saidfirst and second ends of said plunger, whereby said second end of saidplunger can be detached from said first end when said adapter and needleare withdrawn into the interior of the barrel, leaving said first end insaid barrel, said second end being attachable to said structure at thedistal end of the barrel.
 9. A syringe according to claim 6 including analignment surface carried by said plunger and cooperable with anotheralignment surface of said syringe to orient said plunger relative tosaid adapter so that said drive surfaces carried by the plunger lie incircumferential registration with the drive surfaces of said adapterwhen said plunger is moved into its axially distal-most engaged positionrelative to said adapter.
 10. A syringe according to claim 6 whereinsaid adapter engagement and connection engagement structures on saidplunger and adapter, respectively, include alignment surfaces engageablewith one another in response to axial movement of said plunger towardsaid adapter causing orientation of said plunger and said adapterrelative to one another to enable said drive surfaces to lie incircumferential opposition to one another.
 11. A syringe according toclaim 10 wherein said alignment surfaces are inclined to the axis of thebarrel and engage one another in response to axial movement of theplunger toward the adapter to cause relative rotation between saidplunger and said adapter to bring said drive surfaces into engagementwith one another.
 12. A syringe according to claim 10 wherein saidsecond end of said plunger has structure for connecting said plungersecond end with structure adjacent the distal end of the barrel,rupturable structure intermediate said first and second ends of saidplunger for detachably connecting said first and second ends of saidplunger, whereby said second end of said plunger can be detached fromsaid first end when said adapter and needle are withdrawn into theinterior of the barrel, leaving said first end in said barrel, saidsecond end being attachable to said structure at the distal end of thebarrel.
 13. A syringe according to claim 6 wherein said connectivesurfaces include a radial extending projection carried by one of saidplunger and said adapter and a recess carried by another of said plungerand said adapter for receiving said projection.
 14. A syringe accordingto claim 6 wherein said connective surfaces include a pair ofcircumferentially spaced radially extending projections carried by oneof said plunger and said adapter and grooves carried by another of saidplunger and said adapter for receiving said projections.
 15. A syringeaccording to claim 6 wherein said connective surfaces include a radialextending projection carried by one of said plunger and said adapter anda groove carried by another of said plunger and said adapter forreceiving said projection in response to relative rotation of saidplunger and said adapter.
 16. A syringe according to claim 6 whereinsaid connective surfaces include a pair of radial extending projectionscarried by said plunger and a pair of grooves carried by said adapterfor receiving said projections, respectively, in response to relativerotation of said plunger and said adapter.
 17. A syringe according toclaim 16 wherein said plunger includes rupturable structure intermediatesaid first and second ends thereof for detachably connecting said firstand second ends relative to one another whereby said second end can bedetached from said first end when said adapter and needle are withdrawninto the interior of the barrel, including an alignment surface carriedby said plunger and cooperable with another alignment surface of saidsyringe to orient said plunger relative to said adapter so that saiddrive surfaces carried by the plunger lie in circumferentialregistration with the drive surfaces of said adapter when said plungeris moved into its axially distal-most engaged position relative to saidadapter.